CN114370028A - A kind of laying method of geomembrane on breccia base - Google Patents

Abstract

The invention discloses a method for laying a geomembrane on a breccia base, and relates to the field of hydraulic engineering. In the present application, the foundation surface, the lower cushion layer, the lower protective layer, the multi-layer composite geomembrane, the upper protective layer, the upper cushion layer and the protective layer are sequentially layered from bottom to top, and the geomembrane is laid on the breccia base. Among them, the non-woven fabric is completely soaked in the modified polyethylene, and the methoxy and hydroxyl groups on the modified polyethylene react with the hydroxyl and carboxyl groups on the non-woven fabric, and are firmly attached to the interior and surface of the non-woven fabric to obtain a composite geotextile. Then, the modified silica gel is wrapped around the composite geomembrane, and the formic acid group in the modified silica gel reacts with the hydroxyl group on the surface of the composite geomembrane to form a covalent bond and cross-linking, which is firmly attached to the surface of the composite geomembrane. During the thermal curing process, the wrapping process The generated carbonic acid is decomposed into carbon dioxide gas, and a porous structure is formed on the surface of the composite geomembrane to obtain a multi-layer composite geomembrane with excellent tensile strength, aging resistance and stability.

Description

A kind of laying method of geomembrane on breccia base

technical field

The invention relates to the field of hydraulic engineering, in particular to a method for laying a geomembrane on a breccia base.

Background technique

When constructing plain reservoirs, when the reservoir area lacks impermeable strata of effective thickness, it is usually necessary to adopt the horizontal anti-seepage scheme of the entire reservoir bottom. For reservoirs using geomembrane reservoirs for seepage control, due to the huge area of reservoirs, such as Xincheng Reservoir in Zibo City, Shandong Province, the whole reservoir is covered with plastic about 1.0km2; the expansion and reconstruction project of Xixia Reservoir has an area of 2.09km2; The width is about 2km, and the water storage area of the reservoir is nearly 6km2, so it is very important to choose the appropriate anti-seepage structure and laying method of the geomembrane.

In view of the important position of geomembrane in the anti-seepage structure of the warehouse, Article 2.3.1 of "Technical Specifications for Polyethylene (PE) Geomembrane Anti-seepage Engineering" (SL/T231-98) stipulates that "the structure of geomembrane anti-seepage engineering should be based on The specific requirements of the project are determined, and the structural design of the project should include the following three contents: the design of the lower support layer, the design of the anti-seepage layer of the geomembrane, and the design of the upper protective layer.” However, the separation of breccia soil in the reservoir area is poor. The general particle size is 20-50mm, the maximum particle size is 130mm, and the particle size larger than 2mm accounts for 60-80% of the total weight. The composition is sandstone, limestone, etc., and is filled with coarse and fine sand. According to Appendix A of "Technical Specifications for Polyethylene (PE) Geomembrane Anti-seepage Engineering" (SL/T231-98), "the support layer shall include the upper cushion layer and the lower transition layer", and "the transition layer shall have a particle size of 5 -15cm crushed stone", "the cushion material is laid on the transition layer, and its particle size is determined according to the thickness of the geomembrane: when the film thickness is about 1mm, the cushion layer is made of crushed stone with a particle size of less than 1cm or pebbles or gravel with a particle size of less than 2cm; The thickness of the cushion layer is about 0.6cm and the particle size is less than 0.5cm.”, “If a composite geomembrane with a PE geomembrane sandwiched between two layers of non-woven fabrics is used, the particle size of the cushion material can be thickened, and the particle size of the cushion layer can be increased. Pebble or gravel less than 4 cm in diameter". The fine sand layer distributed on site, light yellow, gray, slightly dense to dense state, saturated, contains a small amount of breccia 5-6cm.

In summary, the stratum of the reservoir area is mainly distributed with breccia, which contains a large number of breccias with a particle size of 2-13 cm, which is poor in sorting, and there are also a small number of breccias with a particle size of 2-6 cm in the fine sand on site, which is not suitable for geomembrane control. The infiltration scheme brings serious engineering problems. The present invention modifies and lays the geomembrane, and builds the reservoir under the conditions of quality assurance and economical practicability.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for laying a geomembrane on a breccia base to solve the problems existing in the prior art.

In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions:

The invention discloses a method for laying geomembrane on a breccia base, which consists of laying a base surface, a lower cushion layer, a lower protective layer, a multi-layer composite geomembrane, an upper protective layer, an upper cushion layer and a protective layer in sequence from bottom to top.

Further, the laying method of the geomembrane on the breccia base mainly comprises the following preparation steps:

(1) Laying of foundation surface: excavate an earthwork with a length of 100-120m, a width of 6-6.5m and a depth of 3-3.5m, use a 22t road roller to flatten the site, and compact and flatten the breccia soil foundation surface. The relative density is 0.75-0.8; small excavators are used to excavate exhaust blind ditch at 0.8-1m on the four sides of the earthwork, horizontal blind ditch is set every 15-20m within the vertical blind ditch, and 300g/g/ m ² geotextile 600～720m ² , fill with pebbles and exhaust pipe, then lay 300g/m ² geotextile 600～720m ² , level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and sieve the thickness of the fine sand layer of 10-15cm. After watering, use a 22t road roller to compact and roll it, and the surface is leveled by pulling the wire to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the multi-layer composite geomembrane and the upper protective layer: laying the lower protective layer 300g/m ² geotextile 610 ~ 730m ² , the edge line should exceed the laying edge line of the multi-layer composite geomembrane on the cloth by 50 ~ 60cm, the geotextile connection adopts 250℃ hot air welding, the lap width is 10cm, and the laying and connection of the lower protective layer are completed; 600-720m2 multi ^- layer composite geomembrane is then laid, using 350℃ double seam heat sealing welding, the lap width is 10cm, Complete the laying and connection of multi-layer composite geomembrane; then lay a protective layer of 300g/m ² geotextile 610 ~ 730 m ² , and connect it by hot air welding at 250°C, with a lap width of 10cm, to complete the laying and connection of the upper protective layer;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the starting laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 40~ 45cm; use a crawler-type excavator to lay the covering layer with a thickness of 0.5-0.8m, and use a grader to level the covering soil layer to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and level 0.6-0.8 m; the crawler excavator is used to lay the covering layer. The thickness of the overburden layer is 0.95-1m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch in step (1) is a long-side blind ditch with a distance of 0.8 to 1 m from the inside of the broad side and the long side of the earthwork and a length of 98 to 118 m; when the exhaust blind ditch is laid, the air is exhausted. After the pipe is laid inside the blind ditch, the blind ditch is filled and paved with pebble material; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the preparation method of the multi-layer composite geomembrane described in step (3) is as follows:

a. Add polyvinyl chloride alcohol to deionized water with 1 to 2 times the mass of polyvinyl chloride alcohol at 90 to 95°C, 800 r/min and stir for 30 minutes, and add 0.25 to 0.5 times the mass of polyvinyl chloride alcohol to trimethylsiloxypyruvic acid. Continue stirring in sodium for 5 hours, add 1,2-epoxy-3-aminobutanol with a mass of 0.25 to 0.5 times the mass of polyvinyl chloride alcohol, and continue stirring at 80°C for 3 hours to obtain a modified polyethylene film liquid;

b. Add the hydroxyl-terminated polychlorosiloxane into anhydrous toluene with 12.5-13 times the mass of the hydroxyl-terminated polychlorosiloxane, stir at 800 r/min and reflux for 1 h in an oil bath at 110 °C, add the hydroxyl-terminated polychlorosiloxane After 1.5-2 times the mass of alkane, epoxy trimethoxysilane continued to reflux for 1 h, put it into a vacuum rotary evaporator and heat up to 110 ° C, and take out when the mass of toluene was 5 times the mass of nano-silica sol by vacuum rotary distillation at 160 r/min. Add potassium diformate with 3-3.2 times the mass of hydroxyl-terminated polysiloxane under ice bath condition at 4°C and mix to obtain modified silica gel;

c. Under the condition of 75～85℃ and 10Pa vacuum, immerse the non-woven fabric in the modified polyethylene film liquid with 3.8～4.2 times the mass of the non-woven fabric, soak it for 24 hours and then soak it out, then cool it to room temperature and air dry to obtain 0.64 ~0.72mm thick composite geomembrane;

d. Stir and mix the modified silica gel and ethyl orthosilicate with a mass of 0.02 to 0.03 times the modified silica gel at room temperature and 300 r/min for 5 min to obtain a modified silica gel mixture; then the modified silica gel mixture is removed under a vacuum of 10 Pa. Soak for 5 minutes to obtain the deaerated modified silica gel mixture; immerse the composite geomembrane in the modified silica gel mixture with 2.5 to 3 times the mass of the composite geomembrane, immerse it for 24 hours, remove it, and cure it at 60 °C for 16 hours to obtain the thickness of the surface layer It is a multi-layer composite geomembrane of 0.8 to 1.2 mm.

Further, the non-woven fabric in step c is a 0.56 mm thick seaweed fiber non-woven fabric.

Compared with the prior art, the beneficial effects achieved by the present invention are:

In the present invention, when laying the geomembrane on the breccia base, the non-woven fabric is completely soaked in the modified polyethylene to obtain a composite geomembrane, and then the composite geomembrane is wrapped and thermally cured with modified silica gel to obtain a multi-layer composite geomembrane. The geomembrane is then laid from bottom to top according to the base surface, the lower cushion layer, the lower protective layer, the multi-layer composite geomembrane, the upper protective layer, the upper cushion layer and the protective layer; the modified polyethylene is made of trimethylsiloxy It is prepared by mixing sodium pyruvate, 1,2-epoxy-3-aminobutanol and polyvinyl alcohol; modified silica gel is prepared by mixing modified polychlorosiloxane with potassium diformate; modified polychlorosilicone Alkane is prepared by mixing hydroxy-terminated polychlorosiloxane and epoxy trimethoxysilane.

First, add sodium trimethylsiloxypropionate and 1,2-epoxy-3-aminobutanol to polyvinyl chloride alcohol, and one end of sodium trimethylsiloxypyruvate is firmly broken by ionic bond ground grafted on polyvinyl chloride alcohol, the epoxy group in 1,2-epoxy-3-aminobutanol is ring-opened under the nucleophilic action of hydroxyl group on polyvinyl chloride alcohol, and grafted on polyvinyl chloride alcohol molecule On the chain, modified polyethylene is obtained; wherein, sodium trimethylsiloxypyruvate is demethoxylated and reacted with hydroxyl groups on the non-woven fabric to be firmly grafted on the non-woven fabric, and the modified polyethylene and the non-woven fabric are stably grafted on the non-woven fabric. The cloth fibers are closely cross-linked together, which increases the tensile strength of the composite geomembrane; the hydroxyl groups in 1,2-epoxy-3-aminobutanol and the carboxyl groups on the non-woven fabric undergo an esterification reaction and are firmly grafted to the composite geomembrane. On the non-woven fabric, the modified polyethylene and the non-woven fabric fibers are further connected together, and the carbonyl group on the 1,2-epoxy-3-aminobutanol reacts with the sodium trimethylsiloxypyruvate to form The stable diamine bridge bonds make the modified polyethylene cross-link between the fibers of the non-woven fabric to form a dense network cross-linked structure to reduce the gaps on the non-woven fabric. By covalently grafting together, a dense waterproof membrane is formed inside and on the surface of the non-woven fabric, thereby increasing the aging resistance of the composite geomembrane.

Secondly, the hydroxyl-terminated polychlorosiloxane and epoxy trimethoxysilane are mixed and grafted together by the dehydrogenation of hydroxyl groups in the hydroxyl-terminated polychlorosiloxane and the demethoxylation of epoxy trimethoxysilane to prepare The modified polychlorosiloxane is obtained; the modified polychlorosiloxane is mixed with potassium diformate, and a covalent bond is formed between the dechlorination of the modified polychlorosiloxane and the diformic acid under the action of potassium ions in potassium diformate Branches together to obtain modified silica gel, the composite geomembrane is wrapped and thermally cured with the modified silica gel, and the formic acid group in the modified silica gel reacts with the hydroxyl groups on the surface of the composite geomembrane to form covalent bond cross-linking, so that the modified silica gel is stabilized It is attached to the surface of the composite geomembrane to obtain a multi-layer composite geomembrane; the epoxy group in the modified silica gel opens a ring under the nucleophilic action of the amino group on the surface of the composite geomembrane to form a covalent bond cross-linking, which further makes the modified silica gel firmly attached. On the surface of the composite geomembrane; while the modified silica gel is cured by heating during the impregnation, the carbonic acid generated by the reaction between the formic acid group and the hydroxyl group in the impregnation system is heated and decomposed into carbon dioxide gas, so that the surface of the multi-layer composite geomembrane forms a porous structure. After being subjected to external force, the stress is dispersed in the interior through the pores, which increases the stability of the multi-layer composite geomembrane when it vibrates.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In order to illustrate the method provided by the present invention in detail by the following examples, the test methods of each index of the geomembrane on the breccia base laid by the laying method of the geomembrane on the breccia base in the following examples are as follows:

Stability: The stability of the geomembrane on the breccia base laid by the laying method of the geomembrane on the breccia base of the embodiment and the comparative example is measured according to the GB/T18258 standard method to determine the stability.

Tensile strength: The tensile strength of the geomembrane on the breccia base laid by the laying method of the geomembrane on the breccia base of the embodiment and the comparative example is measured according to the standard methods of GB/T1040 and GB/T10654.

Aging resistance: The aging resistance was determined by measuring the tensile strength before and after aging of the geomembrane on the breccia substrate laid by the laying method of the example and the comparative example.

Example 1

A method for laying a geomembrane on a breccia base, mainly comprising the following preparation steps:

(1) Laying of the foundation surface: dig an earthwork with a length of 100m, a width of 6m and a depth of 3m, use a 22t road roller to flatten the site, and compact and flatten the breccia soil foundation surface, with a relative density of 0.75; Small excavators are used to excavate exhaust blind ditch at 0.8m ^on the ^four sides, and horizontal blind ditch is set every 15m within the range of vertical blind ditch. trachea, then lay 300g/m ² geotextile 600m ² , level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and screen the fine sand with a thickness of 10cm. After watering, a 22t road roller is used to compact and roll, and the surface is leveled by pulling the wire to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the multi-layer composite geomembrane and the upper protective layer: lay the lower protective layer 300g/m ² geotextile 610m ² , and the edge line should exceed the upper multi-layer composite geomembrane laying edge line 50cm, geotextile The connection adopts 250 ℃ hot air welding, the lap width is 10cm, and the laying and connection of the lower protective layer are completed; 600m2 multi ^- layer composite geomembrane is then laid, and 350 ℃ double seam heat sealing welding is used, and the lap width is 10cm, and the multi-layer composite geomembrane is completed. Laying and connecting; then lay a protective layer of 300g/m ² geotextile 610m ² , and connect it by hot air welding at 250°C, with a lap width of 10cm, to complete the laying and connection of the upper protective layer;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the starting laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 40cm; Crawler-type excavators are used to lay the covering soil layer, the thickness of the covering soil cushion layer is 0.5m, and the covering soil cushion layer is leveled with a grader to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and lay 0.6m; The thickness is 0.95m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch described in step (1) is a long side blind ditch with a distance of 0.8m from the broad side of the earthwork and the long side and a length of 98m; when the exhaust blind ditch is laid, the exhaust pipe is laid on the After the inside of the blind ditch, use pebble material to fill the gap and pave the blind ditch; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the preparation method of the multi-layer composite geomembrane described in step (3) is as follows:

a. Add polyvinyl chloride alcohol to deionized water with 1 times the mass of polyvinyl chloride alcohol and stir for 30 minutes at 90°C and 800 r/min, add 0.25 times the mass of polyvinyl chloride alcohol to sodium trimethylsiloxypyruvate and continue stirring for 5 hours, Add 1,2-epoxy-3-aminobutanol with a mass of 0.25 times the mass of polyvinyl chloride alcohol and continue stirring at 80°C for 3 hours to obtain a modified polyethylene film liquid;

b. Add the hydroxyl-terminated polychlorosiloxane into anhydrous toluene with 12.5 times the mass of the hydroxyl-terminated polychlorosiloxane, stir at 800 r/min and reflux for 1 h in an oil bath at 110°C, add the mass of the hydroxyl-terminated polychlorosiloxane After 1.5 times of epoxy trimethoxysilane was refluxed for 1 hour, it was put into a vacuum rotary evaporator and heated to 110 °C, and the toluene quality was 5 times the mass of nano-silica sol by vacuum rotary evaporation at 160 r/min. Under bath conditions, potassium diformate with 3 times the mass of hydroxyl-terminated polychlorosiloxane is added and mixed to obtain modified silica gel;

c. Under the condition of 75℃ and 10Pa vacuum, the non-woven fabric was immersed in the modified polyethylene film solution with 3.8 times the mass of the non-woven fabric, soaked for 24 hours, soaked and pulled out, then cooled to room temperature, and air-dried to obtain a 0.64mm thick composite geotextile membrane;

d. Stir and mix the modified silica gel and ethyl orthosilicate with a mass of 0.02 times the modified silica gel at room temperature and 300 r/min for 5 min to obtain a modified silica gel mixture; then the modified silica gel mixture is degassed under a vacuum of 10 Pa for 5 min , to obtain the modified silica gel mixture after defoaming; immerse the composite geomembrane in the modified silica gel mixture 2.5 times the mass of the composite geomembrane, immerse it for 24 hours, and remove it. Multilayer composite geomembrane.

Further, the non-woven fabric in step c is a 0.56 mm thick seaweed fiber non-woven fabric.

Example 2

A method for laying a geomembrane on a breccia base, mainly comprising the following preparation steps:

(1) Laying of foundation surface: excavate an earthwork with a length of 110m, a width of 6.25m and a depth of 6.25m, use a 22t road roller to level the site, and compact and level the breccia soil foundation surface, with a relative density of 0.775; A small excavator is used to excavate exhaust blind ditch at 0.9m ^on the ^four sides of the earthwork, and a horizontal blind ditch is set every 17.5m within the vertical blind ditch. materials and exhaust pipes, then lay 660m ² of 300g/m ² geotextile, level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and screen the fine sand with a thickness of 12.5cm. After watering, a 22t road roller is used for compaction and rolling, and the surface is leveled by pulling wires to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the multi-layer composite geomembrane and the upper protective layer: lay the lower protective layer 300g/m ² geotextile 670m ² , and the edge line should exceed the multi-layer composite geomembrane laying edge line 55cm, geotextile The connection adopts 250 ℃ hot air welding, the lap width is 10cm, and the laying and connection of the lower protective layer are completed; 660m2 multi ^- layer composite geomembrane is then laid, and 350 ℃ double seam heat sealing welding is used, and the lap width is 10cm to complete the multi-layer composite geomembrane. Laying and connecting; then lay a protective layer of 300g/m ² geotextile 670m ² , and connect it by hot air welding at 250°C, with a lap width of 10cm, to complete the laying and connection of the upper protective layer;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the starting side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 42.5cm. ; Use a crawler excavator to lay the covering soil layer, the thickness of the covering soil cushion layer is 0.65m, and use a grader to level the covering soil layer to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the starting side of the multi-layer composite geomembrane, and the loader is used with the grader to pave and lay 0.7m; The thickness is 0.975m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch described in step (1) is a long-side blind ditch with a distance of 0.9m from the broad side of the earthwork and the inner side of the long side and a length of 108m; when the exhaust blind ditch is laid, the exhaust pipe is laid on the After the inside of the blind ditch, use pebble material to fill the gap and pave the blind ditch; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the preparation method of the multi-layer composite geomembrane described in step (3) is as follows:

a. Add polyvinyl chloride alcohol to deionized water with 1.5 times the mass of polyvinyl chloride alcohol at 92.5°C and stir at 800 r/min for 30 minutes, add 0.375 times the mass of polyvinyl chloride alcohol to sodium trimethylsiloxypyruvate and continue stirring for 5 hours, Add 1,2-epoxy-3-aminobutanol with a mass of 0.375 times the mass of polyvinyl chloride alcohol and continue stirring at 80°C for 3 hours to obtain a modified polyethylene film liquid;

b. Add the hydroxyl-terminated polychlorosiloxane into anhydrous toluene with 12.75 times the mass of the hydroxyl-terminated polychlorosiloxane, stir at 800 r/min and reflux for 1 hour in an oil bath at 110°C, and add the mass of the hydroxyl-terminated polychlorosiloxane. After 1.75 times of epoxy trimethoxysilane was refluxed for 1 hour, it was put into a vacuum rotary evaporator and heated to 110 °C, and the toluene mass was 5 times the mass of nano-silica sol by vacuum rotary distillation at 160 r/min. Under bath conditions, potassium diformate with 3.1 times the mass of hydroxyl-terminated polychlorosiloxane was added and mixed to obtain modified silica gel;

c. Under the condition of 80℃ and 10Pa vacuum, the non-woven fabric was immersed in the modified polyethylene film solution with 4 times the mass of the non-woven fabric, soaked for 24 hours, soaked and pulled out, then cooled to room temperature, and air-dried to obtain a 0.68mm thick composite geotextile membrane;

d. Stir and mix the modified silica gel and ethyl orthosilicate with a mass of 0.025 times the modified silica gel at room temperature and 300 r/min for 5 min to obtain a modified silica gel mixture; then the modified silica gel mixture is deaerated under a vacuum of 10 Pa for 5 min , to obtain the modified silica gel mixture after defoaming; immerse the composite geomembrane in the modified silica gel mixture with a mass of 2.75 times the weight of the composite geomembrane, immerse it for 24 hours, remove it, and cure it at 60 °C for 16 hours to obtain a multi-layer composite with a surface thickness of 1 mm. Layer composite geomembrane.

Further, the non-woven fabric in step c is a 0.56 mm thick seaweed fiber non-woven fabric.

Example 3

A method for laying a geomembrane on a breccia base, mainly comprising the following preparation steps:

(1) Laying of the foundation surface: excavate an earthwork with a length of 120m, a width of 6.5m and a depth of 3.5m, use a 22t road roller to level the site, and compact and level the breccia foundation surface, with a relative density of 0.8; A small excavator is used to excavate the exhaust blind ditch at 1m ^on the ^four sides of the earthwork, and a horizontal blind ditch is set up every 20m within the range of the vertical blind ditch. Exhaust pipe, then lay 300g/m ² geotextile 720m ² , level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and screen the fine sand with a thickness of 15cm. After watering, a 22t road roller is used to compact and roll, and the surface is leveled by pulling wires to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the multi-layer composite geomembrane and the upper protective layer: laying the lower protective layer 300g/m ² geotextile 730m ² , the edge line should exceed the upper layer of the multi-layer composite geomembrane laying edge line 60cm, geotextile The connection adopts 250 ℃ hot air welding, the lap width is 10cm, and the laying and connection of the lower protective layer is completed; 720m2 multi ^- layer composite geomembrane is then laid, and 350 ℃ double seam heat welding is used, and the lap width is 10cm, and the multi-layer composite geomembrane is completed. Laying and connecting; then lay a protective layer of 300g/m ² geotextile 730m ² , and connect it by hot air welding at 250°C, with a lap width of 10cm, to complete the laying and connection of the upper protective layer;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the initial laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 45cm; Crawler-type excavators are used to lay the covering soil layer, the thickness of the covering soil cushion layer is 0.8m, and the covering soil cushion layer is leveled with a grader to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and lay 0.8m; The thickness is 1m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch described in step (1) is a long-side blind ditch with a distance of 1m from the broad side of the earthwork and the interior of the long side and a length of 118m; when the exhaust blind ditch is laid, the exhaust pipe is laid on the blind ditch. After the inside of the ditch, use pebble material to fill the gap and pave the blind ditch; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the preparation method of the multi-layer composite geomembrane described in step (3) is as follows:

a. Add polyvinyl chloride alcohol to deionized water with 2 times the mass of polyvinyl chloride alcohol and stir for 30 min at 95°C and 800 r/min, add 0.5 times the mass of polyvinyl chloride alcohol to sodium trimethylsiloxypyruvate and continue stirring for 5 hours, Add 1,2-epoxy-3-aminobutanol with 0.5 times the mass of polyvinyl chloride alcohol and continue to stir at 80°C for 3 hours to obtain a modified polyethylene film liquid;

b. Add the hydroxyl-terminated polychlorosiloxane into anhydrous toluene with 13 times the mass of the hydroxyl-terminated polychlorosiloxane, stir at 800 r/min and reflux for 1 h in an oil bath at 110 °C, add the mass of the hydroxyl-terminated polychlorosiloxane After 2 times of epoxy trimethoxysilane continued to reflux for 1 h, put it in a vacuum rotary evaporator and heat up to 110 ° C, vacuum rotary evaporation at 160 r/min and take out when the mass of toluene is 5 times the mass of nano-silica sol, at 4 ° C on ice Under bath conditions, potassium diformate with 3.2 times the mass of hydroxyl-terminated polychlorosiloxane was added and mixed to obtain modified silica gel;

c. Under the vacuum conditions of 85℃ and 10Pa, the non-woven fabric was immersed in the modified polyethylene film solution with 4.2 times the mass of the non-woven fabric, soaked for 24 hours, soaked and pulled out, then cooled to room temperature and air-dried to obtain a 0.72mm thick composite geotextile membrane;

d. Stir and mix the modified silica gel and ethyl orthosilicate with a mass of 0.03 times the modified silica gel at room temperature and 300 r/min for 5 minutes to obtain a modified silica gel mixture; then the modified silica gel mixture is degassed under a vacuum of 10 Pa for 5 minutes , to obtain the modified silica gel mixture after defoaming; immerse the composite geomembrane in the modified silica gel mixture that is three times the mass of the composite geomembrane, immerse it for 24 hours, and remove it. Multilayer composite geomembrane.

Further, the non-woven fabric in step c is a 0.56 mm thick seaweed fiber non-woven fabric.

Comparative Example 1

A method for laying a geomembrane on a breccia base, mainly comprising the following preparation steps:

(1) Laying of the foundation surface: dig an earthwork with a length of 100m, a width of 6m and a depth of 3m, use a 22t road roller to flatten the site, and compact and flatten the breccia soil foundation surface, with a relative density of 0.75; Small excavators are used to excavate exhaust blind ditch at 0.8m ^on the ^four sides, and horizontal blind ditch is set every 15m within the range of vertical blind ditch. trachea, then lay 300g/m ² geotextile 600m ² , level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and screen the fine sand with a thickness of 10cm. After watering, a 22t road roller is used to compact and roll, and the surface is leveled by pulling the wire to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the composite geomembrane and the upper protective layer: lay the lower protective layer 300g/m ² geotextile 610m ² , the edge line should exceed the edge line of the composite geomembrane laying on the cloth by 50cm, and the geotextile connection should be 250 ℃ Hot air welding, with a lap width of 10cm, completes the laying and connection of the lower protective layer; then lays 600m2 of composite geomembrane, using 350°C ^double seam heat-sealing welding, with a lap width of 10cm, to complete the laying and connection of the composite geomembrane; The protective layer is 300g/m ² geotextile 610m ² , and the 250 ℃ hot air welding connection, the lap width is 10cm, and the laying and connection of the upper protective layer are completed;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the starting laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 40cm; Crawler-type excavators are used to lay the covering soil layer, the thickness of the covering soil cushion layer is 0.5m, and the covering soil cushion layer is leveled with a grader to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and lay 0.6m; The thickness is 0.95m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch described in step (1) is a long side blind ditch with a distance of 0.8m from the broad side of the earthwork and the long side and a length of 98m; when the exhaust blind ditch is laid, the exhaust pipe is laid on the After the inside of the blind ditch, use pebble material to fill the gap and pave the blind ditch; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the preparation method of step (3) composite geomembrane is as follows:

a. Add polyvinyl chloride alcohol to deionized water with 1 times the mass of polyvinyl chloride alcohol and stir for 30 minutes at 90°C and 800 r/min, add 0.25 times the mass of polyvinyl chloride alcohol to sodium trimethylsiloxypyruvate and continue stirring for 5 hours, Add 1,2-epoxy-3-aminobutanol with a mass of 0.25 times the mass of polyvinyl chloride alcohol and continue stirring at 80°C for 3 hours to obtain a modified polyethylene film liquid;

b. Under vacuum conditions of 75°C and 10Pa, the non-woven fabric was immersed in a modified polyethylene film solution with a mass of 3.8 times the non-woven fabric, soaked for 24 hours, soaked and pulled out, then cooled to room temperature and air-dried to obtain a 0.64mm thick composite geotextile membrane;

Further, the non-woven fabric in step b is a 0.56 mm thick seaweed fiber non-woven fabric.

Comparative Example 2

A method for laying a geomembrane on a breccia base, mainly comprising the following preparation steps:

(1) Laying of the foundation surface: dig an earthwork with a length of 100m, a width of 6m and a depth of 3m, use a 22t road roller to flatten the site, and compact and flatten the breccia soil foundation surface, with a relative density of 0.75; Small excavators are used to excavate exhaust blind ditch at 0.8m ^on the ^four sides, and horizontal blind ditch is set every 15m within the range of vertical blind ditch. trachea, then lay 300g/m ² geotextile 600m ² , level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and screen the fine sand with a thickness of 10cm. After watering, a 22t road roller is used to compact and roll, and the surface is leveled by pulling the wire to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the multi-layer composite geomembrane and the upper protective layer: lay the lower protective layer 300g/m ² geotextile 610m ² , and the edge line should exceed the upper multi-layer composite geomembrane laying edge line 50cm, geotextile The connection adopts 250 ℃ hot air welding, the lap width is 10cm, and the laying and connection of the lower protective layer is completed; 600m2 multi ^- layer composite geomembrane is then laid, and 350 ℃ double seam heat sealing welding is used, and the lap width is 10cm, and the multi-layer composite geomembrane is completed. Laying and connecting; then lay a protective layer of 300g/m ² geotextile 610m ² , and connect it by hot air welding at 250°C, with a lap width of 10cm, to complete the laying and connection of the upper protective layer;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the starting laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 40cm; Crawler-type excavators are used to lay the covering soil layer, the thickness of the covering soil cushion layer is 0.5m, and the covering soil cushion layer is leveled with a grader to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and lay 0.6m; The thickness is 0.95m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch described in step (1) is a long side blind ditch with a distance of 0.8m from the broad side of the earthwork and the long side and a length of 98m; when the exhaust blind ditch is laid, the exhaust pipe is laid on the After the inside of the blind ditch, use pebble material to fill the gap and pave the blind ditch; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the preparation method of the multi-layer composite geomembrane described in step (3) is as follows:

a. Add polyvinyl chloride alcohol to deionized water with 1 times the mass of polyvinyl chloride alcohol and stir for 30 minutes at 90°C and 800 r/min, add 0.25 times the mass of polyvinyl chloride alcohol to sodium trimethylsiloxypyruvate and continue stirring for 5 hours, The modified polyethylene film liquid is prepared;

b. Add the hydroxyl-terminated polychlorosiloxane into anhydrous toluene with 12.5 times the mass of the hydroxyl-terminated polychlorosiloxane, stir at 800 r/min and reflux for 1 h in an oil bath at 110°C, add the mass of the hydroxyl-terminated polychlorosiloxane After 1.5 times of epoxy trimethoxysilane was refluxed for 1 hour, it was put into a vacuum rotary evaporator and heated to 110 °C, and the toluene quality was 5 times the mass of nano-silica sol by vacuum rotary evaporation at 160 r/min. Under bath conditions, potassium diformate with 3 times the mass of hydroxyl-terminated polychlorosiloxane is added and mixed to obtain modified silica gel;

c. Under the condition of 75℃ and 10Pa vacuum, the non-woven fabric was immersed in the modified polyethylene film solution with 3.8 times the mass of the non-woven fabric, soaked for 24 hours, soaked and pulled out, then cooled to room temperature, and air-dried to obtain a 0.64mm thick composite geotextile membrane;

d. Stir and mix the modified silica gel and ethyl orthosilicate with a mass of 0.02 times the modified silica gel at room temperature and 300 r/min for 5 min to obtain a modified silica gel mixture; then the modified silica gel mixture is degassed under a vacuum of 10 Pa for 5 min , to obtain the modified silica gel mixture after defoaming; immerse the composite geomembrane in the modified silica gel mixture 2.5 times the mass of the composite geomembrane, immerse it for 24 hours, and remove it. Multilayer composite geomembrane.

Further, the non-woven fabric in step c is a 0.56 mm thick seaweed fiber non-woven fabric.

Comparative Example 3

A method for laying a geomembrane on a breccia base, mainly comprising the following preparation steps:

(1) Laying of the foundation surface: dig an earthwork with a length of 100m, a width of 6m and a depth of 3m, use a 22t road roller to flatten the site, and compact and flatten the breccia soil foundation surface, with a relative density of 0.75; Small excavators are used to excavate exhaust blind ditch at 0.8m ^on the ^four sides, and horizontal blind ditch is set every 15m within the range of vertical blind ditch. trachea, then lay 300g/m ² geotextile 600m ² , level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and screen the fine sand with a thickness of 10cm. After watering, a 22t road roller is used to compact and roll, and the surface is leveled by pulling the wire to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the multi-layer composite geomembrane and the upper protective layer: lay the lower protective layer 300g/m ² geotextile 610m ² , and the edge line should exceed the upper multi-layer composite geomembrane laying edge line 50cm, geotextile The connection adopts 250 ℃ hot air welding, the lap width is 10cm, and the laying and connection of the lower protective layer are completed; 600m2 multi ^- layer composite geomembrane is then laid, and 350 ℃ double seam heat sealing welding is used, and the lap width is 10cm, and the multi-layer composite geomembrane is completed. Laying and connecting; then lay a protective layer of 300g/m ² geotextile 610m ² , and connect it by hot air welding at 250°C, with a lap width of 10cm, to complete the laying and connection of the upper protective layer;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the starting laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 40cm; Crawler-type excavators are used to lay the covering soil layer, the thickness of the covering soil cushion layer is 0.5m, and the covering soil cushion layer is leveled with a grader to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and lay 0.6m; The thickness is 0.95m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch described in step (1) is a long side blind ditch with a distance of 0.8m from the broad side of the earthwork and the long side and a length of 98m; when the exhaust blind ditch is laid, the exhaust pipe is laid on the After the inside of the blind ditch, use pebble material to fill the gap and pave the blind ditch; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the preparation method of the multi-layer composite geomembrane described in step (3) is as follows:

a. Add polyvinyl chloride alcohol to deionized water with 1 times the mass of polyvinyl chloride alcohol at 90°C, 800 r/min and stir for 30 minutes, add 1,2-epoxy-3-aminobutanol with 0.25 times the mass of polyvinyl chloride alcohol Continue to stir at 80°C for 3h to obtain the modified polyethylene film liquid;

b. Add the hydroxyl-terminated polychlorosiloxane into anhydrous toluene with 12.5 times the mass of the hydroxyl-terminated polychlorosiloxane, stir at 800 r/min and reflux for 1 h in an oil bath at 110°C, add the mass of the hydroxyl-terminated polychlorosiloxane After 1.5 times of epoxy trimethoxysilane was refluxed for 1 hour, it was put into a vacuum rotary evaporator and heated to 110 °C, and the toluene quality was 5 times the mass of nano-silica sol by vacuum rotary evaporation at 160 r/min. Under bath conditions, potassium diformate with 3 times the mass of hydroxyl-terminated polychlorosiloxane is added and mixed to obtain modified silica gel;

c. Under the condition of 75℃ and 10Pa vacuum, the non-woven fabric was immersed in the modified polyethylene film solution with 3.8 times the mass of the non-woven fabric, soaked for 24 hours, soaked and pulled out, then cooled to room temperature, and air-dried to obtain a 0.64mm thick composite geotextile membrane;

d. Stir and mix the modified silica gel and ethyl orthosilicate with a mass of 0.02 times the modified silica gel at room temperature and 300 r/min for 5 min to obtain a modified silica gel mixture; then the modified silica gel mixture is degassed under a vacuum of 10 Pa for 5 min , to obtain the modified silica gel mixture after defoaming; immerse the composite geomembrane in the modified silica gel mixture 2.5 times the mass of the composite geomembrane, immerse it for 24 hours, and remove it. Multilayer composite geomembrane.

Further, the non-woven fabric in step c is a 0.56 mm thick seaweed fiber non-woven fabric.

Comparative Example 4

A method for laying a geomembrane on a breccia base, mainly comprising the following preparation steps:

(1) Laying of the foundation surface: dig an earthwork with a length of 100m, a width of 6m and a depth of 3m, use a 22t road roller to flatten the site, and compact and flatten the breccia soil foundation surface, with a relative density of 0.75; Small excavators are used to excavate exhaust blind ditch at 0.8m ^on the ^four sides, and horizontal blind ditch is set every 15m within the range of vertical blind ditch. trachea, then lay 300g/m ² geotextile 600m ² , level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and screen the fine sand with a thickness of 10cm. After watering, a 22t road roller is used to compact and roll, and the surface is leveled by pulling the wire to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the multi-layer geomembrane and the upper protective layer: lay the lower protective layer 300g/m ² geotextile 610m ² , the edge line should exceed the multi-layer geomembrane laying edge line 50cm, and the geotextile connection adopts 250℃ hot air welding, the lap width is 10cm, the laying and connection of the lower protective layer are completed; 600m2 multi ^- layer geomembrane is then laid, and the double seam heat welding at 350℃ is used to complete the laying and connection of the multi-layer geomembrane. ; Then lay a protective layer of 300g/m ² geotextile 610m ² , and connect it by hot air welding at 250°C, with a lap width of 10cm, to complete the laying and connection of the upper protective layer;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the starting laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 40cm; Crawler-type excavators are used to lay the covering soil layer, the thickness of the covering soil cushion layer is 0.5m, and the covering soil cushion layer is leveled with a grader to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and lay 0.6m; The thickness is 0.95m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch described in step (1) is a long side blind ditch with a distance of 0.8m from the broad side of the earthwork and the long side and a length of 98m; when the exhaust blind ditch is laid, the exhaust pipe is laid on the After the inside of the blind ditch, use pebble material to fill the gap and pave the blind ditch; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the preparation method of the multi-layer geomembrane described in step (3) is as follows:

a. Add the hydroxyl-terminated polychlorosiloxane into anhydrous toluene with 12.5 times the mass of the hydroxyl-terminated polychlorosiloxane, stir at 800 r/min and reflux for 1 h in an oil bath at 110 °C, add the mass of the hydroxyl-terminated polychlorosiloxane After 1.5 times of epoxy trimethoxysilane was refluxed for 1 hour, it was put into a vacuum rotary evaporator and heated to 110 °C, and the toluene quality was 5 times the mass of nano-silica sol by vacuum rotary evaporation at 160 r/min. Under bath conditions, potassium diformate with 3 times the mass of hydroxyl-terminated polychlorosiloxane is added and mixed to obtain modified silica gel;

b. Stir and mix the modified silica gel and ethyl orthosilicate with a mass of 0.02 times the modified silica gel at room temperature and 300 r/min for 5 minutes to obtain a modified silica gel mixture; then the modified silica gel mixture is degassed under a vacuum of 10 Pa for 5 minutes , to obtain the modified silica gel mixture after defoaming; immerse the composite geomembrane in the modified silica gel mixture with a mass of 2.5 times the mass of the geomembrane, immerse it for 24 hours, remove it, and cure it at 60 ° C for 16 hours to obtain a surface thickness of 0.8mm. layer of geomembrane.

Further, the geomembrane described in step b is a polyethylene geomembrane, and the membrane thickness is 0.6 mm.

Comparative Example 5

A method for laying a geomembrane on a breccia base, mainly comprising the following preparation steps:

(1) Laying of the foundation surface: dig an earthwork with a length of 100m, a width of 6m and a depth of 3m, use a 22t road roller to flatten the site, and compact and flatten the breccia soil foundation surface, with a relative density of 0.75; Small excavators are used to excavate exhaust blind ditch at 0.8m ^on the ^four sides, and horizontal blind ditch is set every 15m within the range of vertical blind ditch. trachea, then lay 300g/m ² geotextile 600m ² , level the site with a grader, and complete the laying of the foundation surface;

(2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and screen the fine sand with a thickness of 10cm. After watering, a 22t road roller is used to compact and roll, and the surface is leveled by pulling the wire to complete the laying of the underlying layer;

(3) Laying and connection of the lower protective layer, the geomembrane and the upper protective layer: Lay the lower protective layer 300g/m ² geotextile 610m ² , the edge line should exceed the edge line of the geomembrane laying on the cloth by 50cm, and the geotextile is connected by 250 ℃ hot air welding , the lap width is 10cm, and the laying and connection of the lower protective layer is completed; 600m ² geomembrane is then laid, and double seam heat-sealing welding at 350°C is adopted, and the lap width is 10cm to complete the laying and connection of the geomembrane; and then a protective layer of 300g/ m ² geotextile 610m ² , and 250 ℃ hot air welding connection, lap width 10cm, complete the laying and connection of the upper protective layer;

(4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the starting laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 40cm; Crawler-type excavators are used to lay the covering soil layer, the thickness of the covering soil cushion layer is 0.5m, and the covering soil cushion layer is leveled with a grader to complete the laying of the upper cushion layer;

(5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and lay 0.6m; The thickness is 0.95m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base.

Further, the longitudinal exhaust blind ditch described in step (1) is a long side blind ditch with a distance of 0.8m from the broad side of the earthwork and the long side and a length of 98m; when the exhaust blind ditch is laid, the exhaust pipe is laid on the After the inside of the blind ditch, use pebble material to fill the gap and pave the blind ditch; the model of the exhaust pipe is MY200.

Further, the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles.

Further, the geomembrane in step (3) is a polyethylene geomembrane with a thickness of 0.6 mm.

Example of effect

Table 1 below shows the performance analysis results of the geomembranes on the breccia substrates laid by the methods for laying geomembranes on the breccia substrates of Examples 1 to 3 and Comparative Examples 1 to 5 of the present invention.

Table 1

From the comparison of the experimental data of Example 1, Example 2 and Example 3, it can be found that the tensile properties, stability and aging resistance of the multi-layer composite geomembrane have little change; from the experimental data of Example 1 and Comparative Example 1 It can be found by comparison that when the outer layer of the composite geomembrane is not wrapped by a porous silica gel layer, the external force received by the composite geomembrane during vibration cannot be uniformly dispersed through the internal porous structure, which makes the stability of the composite geomembrane worse; Comparing the experimental data of 1 and Comparative Example 2, it can be found that the composite geomembrane is covalently cross-linked between the non-woven fabric and the polyethylene molecular chain without the modification of 1,2-epoxy-3-aminobutanol. The reduction of molecular chains cannot form diamine bridge bonds, and a stable network structure is formed between substances, and the tensile properties of the geomembrane are reduced. Under the modification of sodium siloxypyruvate, the number of covalently cross-linked molecular chains between non-woven fabrics and polyethylene molecular chains is reduced, and diamine bridge bonds cannot be formed to form a stable network structure between substances. From the comparison of the experimental data of Example 1 and Comparative Example 4, it can be found that when the geomembrane is not soaked in the modified polyethylene film liquid but is a commonly used polyethylene film, there is a lack of non-woven fabrics and modified polyethylene films. The tensile properties and aging resistance of the geomembrane are obviously deteriorated when the network structure is formed by cross-linking of covalent bonds between the vinyl membranes. From the comparison of the experimental data of Example 1 and Comparative Example 5 in the table, it is found that the non-woven fabric is completely soaked in the modified polyethylene, and then the composite geomembrane is wrapped with modified silica gel to obtain a multi-layer composite geomembrane, which can effectively improve the Stability, tensile strength and aging resistance of geomembranes.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is to be defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes within the meaning and scope of the equivalents of , are included in the present invention. Any signs in the claims should not be construed as limiting the involved claim.

Claims (6)

1. the laying method of geomembrane on a breccia base, it is characterized in that, the laying method of geomembrane on the breccia base, from bottom to top, lay down successively base surface, lower cushion, lower protective layer, multi-layer Composite geomembrane, upper protective layer, upper cushion layer and protective layer. 2. the laying method of geomembrane on a kind of breccia base according to claim 1, is characterized in that, mainly comprises following preparation steps: (1) Laying of foundation surface: excavate an earthwork with a length of 100-120m, a width of 6-6.5m and a depth of 3-3.5m, use a 22t road roller to flatten the site, and compact and flatten the breccia soil foundation surface. The relative density is 0.75-0.8; small excavators are used to excavate exhaust blind ditch at 0.8-1m on the four sides of the earthwork, and horizontal blind ditch is set every 15-20m within the vertical blind ditch, and 300g/g/ m ² geotextile 600～720m ² , fill with pebbles and exhaust pipes, lay 300g/m ² geotextile 600～720m ² , level the site with a grader, and complete the laying of the foundation surface; (2) Laying of the lower cushion layer: Use a sieve with a sieve hole diameter of 5mm to screen the site fine sand excavation material, and use a paver to spread the screened fine sand, and use a grader to screen the fine sand. Scrape and sieve the thickness of the fine sand layer of 10-15cm. After watering, use a 22t road roller to compact and roll it, and the surface is leveled by pulling the wire to complete the laying of the underlying layer; (3) Laying and connection of the lower protective layer, the multi-layer composite geomembrane and the upper protective layer: laying the lower protective layer 300g/m ² geotextile 610 ~ 730m ² , the edge line should exceed the laying edge line of the multi-layer composite geomembrane on the cloth by 50 ~ 60cm, the geotextile connection adopts 250℃ hot air welding, the lap width is 10cm, and the laying and connection of the lower protective layer are completed; 600-720m2 multi ^- layer composite geomembrane is then laid, using 350℃ double seam heat sealing welding, the lap width is 10cm, Complete the laying and connection of multi-layer composite geomembrane; then lay a protective layer of 300g/m ² geotextile 610 ~ 730 m ² , and connect it by hot air welding at 250°C, with a lap width of 10cm, to complete the laying and connection of the upper protective layer; (4) The laying of the upper cushion layer; the fine sand is spread and leveled by the loader and the excavator. During the fine sand laying and filling process, the sand is laid from the initial laying side of the multi-layer composite geomembrane, and the thickness of the fine sand laying layer is 40~ 45cm; use a crawler-type excavator to lay the covering layer with a thickness of 0.5-0.8m, and use a grader to level the covering soil layer to complete the laying of the upper cushion layer; (5) Laying of protective layer: The breccia soil is paved from the initial laying side of the multi-layer composite geomembrane, and the loader and grader are used to pave and level 0.6-0.8 m; the crawler excavator is used to lay the covering layer. The thickness of the overburden layer is 0.95-1m. After watering, a 22t road roller is used to flatten it to complete the laying of the protective layer and the laying of the geomembrane on the breccia base. 3. The method for laying geomembrane on a breccia base according to claim 2, wherein the vertical exhaust blind ditch described in step (1) is 0.8 to 1 m from the inner distance of the broad side and the long side of the earthwork A long-sided blind ditch with a length of 98-118m; when the exhaust blind ditch is laid, the exhaust pipe is laid inside the blind ditch, and then the blind ditch is filled with pebble material; The model number is MY200. 4. The method for laying a geomembrane on a breccia base according to claim 3, wherein the upper and lower protective layers in step (3) are both 300 g/m ² filament geotextiles. 5. the laying method of geomembrane on a kind of breccia base according to claim 4, is characterized in that, the preparation method of the described multi-layer composite geomembrane of step (3) is as follows: a. Add polyvinyl chloride alcohol into deionized water with 1 to 2 times the mass of polyvinyl chloride alcohol at 90 to 95°C, and stir at 800 r/min for 30 min, and add 0.25 to 0.5 times the mass of polyvinyl chloride alcohol to trimethylsiloxypyruvic acid. Continue stirring in sodium for 5 hours, add 1,2-epoxy-3-aminobutanol with a mass of 0.25 to 0.5 times the mass of polyvinyl chloride alcohol, and continue stirring at 80°C for 3 hours to obtain a modified polyethylene film liquid; b. Add the hydroxyl-terminated polychlorosiloxane into anhydrous toluene with a mass of 12.5 to 13 times the hydroxyl-terminated polychlorosiloxane, stir at 800 r/min and reflux for 1 h in an oil bath at 110 °C, add the hydroxyl-terminated polychlorosiloxane After 1.5-2 times the mass of alkane, epoxy trimethoxysilane continued to reflux for 1 h, put it in a vacuum rotary evaporator and heat up to 110 ° C, and take out when the mass of toluene was 5 times the mass of nano-silica sol by vacuum rotary distillation at 160 r/min. Add potassium diformate with a mass of 3-3.2 times the mass of hydroxyl-terminated polychlorosiloxane under 4°C ice bath and mix to obtain modified silica gel; c. Under the condition of 75～85℃ and 10Pa vacuum, immerse the non-woven fabric in the modified polyethylene film liquid with 3.8～4.2 times the mass of the non-woven fabric, soak it for 24 hours, soak it out, then cool it to room temperature, and dry it to obtain 0.64 ~0.72mm thick composite geomembrane; d. Stir and mix the modified silica gel and ethyl orthosilicate with a mass of 0.02 to 0.03 times the modified silica gel at room temperature and 300 r/min for 5 min to obtain a modified silica gel mixture; then the modified silica gel mixture is removed under a vacuum of 10 Pa. Soak for 5 minutes to obtain the deaerated modified silica gel mixture; immerse the composite geomembrane in the modified silica gel mixture with a mass of 2.5 to 3 times the weight of the composite geomembrane, immerse it for 24 hours, remove it, and cure it at 60°C for 16 hours to obtain the thickness of the surface layer It is a multi-layer composite geomembrane of 0.8 to 1.2 mm. 6 . The method for laying geomembrane on a breccia base according to claim 5 , wherein the non-woven fabric described in step c is a 0.56 mm thick seaweed fiber non-woven fabric. 7 .