CN116219820A - Control Structure and Construction Method of Root Expansion Deformation of Highway Subgrade Pavement in South Bamboo Forest Area - Google Patents

Abstract

The invention discloses a control structure and construction method for root swelling deformation of roadbed road surface in southern bamboo forest area. The structure includes asphalt pavement structure, ecological curb stone structure and roadbed slope structure. Matching; the ecological curb structure includes an L-shaped body that is narrow at the top and wide at the bottom. The interior of the body is provided with an L-shaped through cavity, and the upper surface of the lower body of the body is provided with a water channel. The upper body and the lower body of the main body are separated from each other with drainage outlets, and the drainage outlets are connected to the L-shaped through-cavity, and the L-shaped through-cavity is connected to the side ditch at the bottom of the slope through rapid flow troughs arranged at intervals along the longitudinal direction of the road; the subgrade slope structure The amount of remnant whip filling in the slope fill layer gradually increases from bottom to top. The invention prevents the bamboo whip from growing into the range of the roadbed and road surface, overcomes the problem of root swelling damage, controls the deformation of the roadbed and the road surface, and improves the durability of the road surface.

Description

Control Structure and Construction Method of Root Expansion Deformation of Highway Subgrade Pavement in South Bamboo Forest Area

technical field

The invention belongs to the technical field of road construction and maintenance, and relates to a structure and construction method for regulating root swelling deformation of a roadbed and pavement in a southern bamboo forest area.

Background technique

Moso bamboo is widely distributed in the Yangtze River Basin and southern provinces in my country, and is one of the fastest growing plants in the world. Phyllostachys pubescens runs across the soil within a depth of 40cm below the surface. It has the habit of growing in loose and fertile soil, sunny and warm directions. It likes warm and humid climates, leeward to the sun, humid environments, and rich in organic matter and Acidic soil with mineral elements.

Engineering practice has found that roadbed and pavement diseases caused by the lateral growth of Moso bamboo shoots are common in roads in bamboo forest areas in the south. When building roads in the bamboo forest area, if you encounter a low-lying road section, you often pass it in the form of a low embankment. Although the moso bamboo and its broken whips on the ground will be removed when the embankment is built, due to the tenacious life of the bamboo whips, once the broken whips are not completely removed, the bamboo whips will continue to spread in the embankment; at the same time, the bamboo whips outside the embankment may also spread to The direction of the embankment grows laterally. Due to the habit of growing up along the slope, a large number of bamboo whips will grow up along the slope after invading the embankment area, and finally invade the road shoulder or even the carriageway area. The spreading and growth of bamboo whips in the subgrade soil will generate jacking force on the upper soil. Due to the high degree of compaction and low compressibility of the subgrade soil, the jacking force and deformation of the soil layer will continue to be transmitted upwards, causing swelling of the subgrade soil and pavement structure Deformation, which in turn causes excessive bumps and cracks in the pavement. Moreover, due to the continuous growth of moso bamboo whips, the problems of road surface uplift and cracking will continue to intensify over time, which will not only increase the frequency of road maintenance and cause direct economic losses, but also greatly affect driving safety and road appearance. The above subgrade and pavement diseases are very common in ordinary national roads and local roads in southern mountainous areas, and they are difficult problems to be solved urgently in the improvement and reconstruction of roads in southern bamboo forest areas.

To sum up, in order to prevent the root swelling deformation disease of the highway subgrade pavement in the southern bamboo forest area and ensure the normal service life of the road pavement, it is very necessary to develop a control structure and construction method for the root swelling deformation of the road subgrade pavement in the southern bamboo forest area.

Contents of the invention

In order to solve the above-mentioned problems, the present invention provides a control structure for root swelling deformation of highway subgrade pavement in southern bamboo forest area, which prevents bamboo whips from growing within the range of road subgrade pavement, overcomes the problem of root swelling damage, controls the deformation of roadbed and road surface, and improves pavement durability.

Another object of the present invention is to provide a construction method for the control structure of the root swelling deformation of the subgrade road surface of the southern bamboo forest area.

The technical solution adopted in the present invention is a control structure for controlling root swelling deformation of road subgrade pavement in southern bamboo forest area, including:

Asphalt pavement structure, the thickness of the asphalt pavement structure matches the depth of bamboo whip growth underground, and the surface layer of the pavement structure is provided with a drainage transverse slope;

Ecological curb structure. The ecological curb structure includes an L-shaped body that is narrow at the top and wide at the bottom. The interior of the body is provided with an L-shaped through cavity. The upper surface of the lower body of the body is provided with a waterway. It runs along the length of the main body; the upper body and the lower body of the main body are separated by drainage outlets, and the drainage outlets communicate with the L-shaped through-cavity. ;

The embankment side slope structure, the remnants filling amount in the side slope filling layer of the roadbed side slope structure gradually increases from the bottom to the top soil layer.

Further, the raw materials of the ecological curb structure are composed of the following parts by weight: 20-70 parts of excavated stone, 10-20 parts of calcium hydroxide, 8-15 parts of fly ash, 2-5 parts of bamboo and wood fiber, silicon 8-16 parts of salt cement, 5-15 parts of alicyclic epoxy resin, and 1-6 parts of water; wherein, the bamboo wood fiber is the granular residual whip of moso bamboo.

Further, the asphalt pavement structure adopts a skeleton-dense structure with a porosity of 4-6%.

Further, the asphalt pavement structure includes a lower base layer, an upper base layer, a lower layer, and an upper layer from bottom to top, the lower base layer adopts a lime fly ash stabilized base layer, the upper base layer adopts a lime fly ash stabilized sand and gravel base layer, and the lower layer Medium-grained asphalt concrete is used; fine-grained modified asphalt concrete is used for the upper layer; between the upper layer and the lower layer, and between the lower layer and the upper base layer, the modified emulsified asphalt adhesive layer is used for bonding.

Further, the water channel is formed by a downward depression of an L-shaped bend along the height direction of the body, and the cross section is arc-shaped.

Further, the drain includes a high drain and a low drain, the high drain is set on the upper part of the body, higher than the waterway; the level of the low drain is flush with the road surface structure, and the distance between the drains is 15-20cm .

Further, the drainage outlet is arched, and the drainage outlet is provided with an arched trash-stop, and the hole diameter of the trash-stop is 5-20mm.

Further, the subgrade of the subgrade slope structure includes a lower embankment, an upper embankment, a lower road bed, and an upper road bed from bottom to top, and the side slopes on both sides of the asphalt pavement structure above the upper road bed are filled with roadside fill layers; The side slopes on both sides of the subgrade include the fourth side slope filling layer, the third side slope filling layer, the second side slope filling layer, and the first side slope filling layer from bottom to top. The mass fraction of whip is 8%-14%, and it shows an increasing trend from bottom to top.

Further, the slope surface of the subgrade slope structure is provided with a slope crushed stone layer and a vegetation layer in turn, and in the vegetation layer, there are inserted residual whips with a length of 8 to 10 cm in the horizontal direction, and the mass fraction of the residual whips added is 9% to 11%.

A construction method for the control structure of the root swelling deformation of the subgrade road surface of the southern bamboo forest area, comprising the following steps:

S1, pave the roadbed;

S2. Lay a slope gravel layer on the outside of the roadbed slope, and hang a net on the slope;

S3, spraying the vegetation layer on the slope gravel layer;

S4. Lay the asphalt pavement structure on the leveled roadbed, and the surface layer of the pavement structure is provided with a drainage cross slope;

S5. Set up ecological curb structures on both sides of the road surface. The embedded section of the ecological curb stone structure is buried under the road surface, and the exposed section above the road surface is planed, leveled, and compacted according to the position flush with the road surface, and then installed. An opening is set every 10-15m to connect the L-shaped through cavity inside the ecological curb structure with the rapids. Fill joints between pavement structures.

The beneficial effects of the present invention are:

1. There are two beneficial effects in the roadbed slope structure of the present invention. Firstly, use the road cutting or tunnel excavated stones to be crushed and filled on the outside of the embankment slope to form a slope gravel layer, and the purpose of preventing the growth of bamboo whips is achieved by embedding and compacting between the gravels; secondly, adding The residual whip plays the purpose of reinforcing the vegetation layer and inhibiting the growth of the bamboo whip in the vegetation layer.

2. There are three beneficial effects in the bamboo whip aggregate ecological curbstone of the present invention. First of all, make full use of waste materials to make recycled road engineering blocks, so as to achieve real resource utilization of waste materials; secondly, according to the characteristics of bamboo whip shallow growth and hard avoidance, use the embedding section of curbs buried at a certain depth underground It can effectively resist the extension of bamboo whips; finally, the structure adopts an L-shaped cavity through structure, which has a large flow rate and can timely remove accumulated water on the road.

3. The asphalt concrete of the present invention has three beneficial effects. First of all, the structure adopts a skeleton-dense structure with small porosity, which can effectively prevent bamboo whips from entering the road surface and causing damage to the pavement structure; secondly, this asphalt concrete uses bamboo and wood fiber in the surface material (granular residual whip) as an additive, has good anti-deformation ability, and effectively resists the deformation of the road surface caused by the invasion of bamboo whips; finally, lime fly ash is used to stabilize the base layer, and quicklime is easy to form hydrogen when it encounters humid air. Calcium oxide can effectively inhibit the growth of bamboo whip.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Fig. 2 is a partial view on the right side of Fig. 1 .

FIG. 3 is a partial view on the left side of FIG. 1 .

Fig. 4 is a schematic structural view of a curb in an embodiment of the present invention.

Fig. 5 is the test data of the mechanical properties of curb stones of the embodiment of the present invention and the comparative example.

Fig. 6 is the test data of curb drainage performance of the embodiment of the present invention and the comparative example.

In the figure, 1. Ecological curb structure, 2. Asphalt pavement structure, 20. Body, 21. High drain, 22. Water passage, 23. Low drain, 24. Exposed section, 25. Embedded section, 26. Auxiliary drainage channel, 27. Main drainage channel, 3. Surface layer of pavement structure, 4. Upper layer, 5. Lower layer, 6. Upper base layer, 7. Lower base layer, 8. Road side fill layer, 9. Upper road bed, 10 .Lower road bed, 11. Upper embankment, 12. Lower embankment; 13. First slope fill layer, 14. Second slope fill layer, 15. Third slope fill layer, 16. Fourth side Slope fill layer, 17. Rapid flow trough, 18. Side ditch, 19. Vegetation layer.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1,

A control structure for root swell deformation of highway subgrade pavement in the southern bamboo forest area, as shown in Figure 1, includes asphalt pavement structure 2, ecological curb structure 1, and subgrade slope structure, which together form a stable control structure for root swell deformation of roadbed pavement.

As shown in Figure 2, the thickness of the asphalt pavement structure 2 is 40cm, which corresponds to the depth of bamboo whip growth underground. The asphalt pavement structure is composed of the lower base layer 7, the upper base layer 6, the lower layer 5, and the upper layer 4 from bottom to top; The asphalt pavement structure includes the surface layer and the base layer. From bottom to top, the lower base layer 7 is stabilized with 7% lime fly ash; Granular asphalt concrete; 50% emulsified asphalt adhesive layer oil is used for bonding between the surface layer and the base layer, and the upper layer 4 is made of 6-10 cm fine-grained modified asphalt concrete; the thickness of the lower base layer 7 is 15-20 cm, and the thickness of the upper base layer 6 is 25 cm. ~30cm, with sufficient strength to resist bamboo whips.

Between the upper layer 4 and the lower layer 5, and between the lower layer 5 and the upper base layer 6, the modified emulsified asphalt adhesive layer is used for bonding, which can strengthen the bonding between the surface layers, so that the adjacent surface layer and the base layer It can be bonded into a firm whole to prevent sliding or pushing between adjacent two layers, and in the pavement structure, in order to ensure the compactness of the pavement structure, its water permeability is not strong, and the modified emulsified asphalt is bonded Layer bonding can play a certain role in waterproofing, improving the strength, stability and waterproofing capacity of the pavement. The lower seal layer is made of modified asphalt with gravel evenly distributed on the surface. The modified asphalt is SBS modified asphalt, which can effectively change the structural strength of the pavement and effectively resist the damage of plant roots such as bamboo whips to the pavement.

In the embodiment, the thickness of the upper layer 4 is 6-10 cm, and the thickness of the lower layer 5 is 8-12 cm. The modified emulsified asphalt adhesive layer adopts PC-3 emulsified asphalt, and the spraying amount of PC-3 emulsified asphalt is 0.4-0.6 L/m ² .

As shown in Figure 4, the ecological curb structure 1 includes a body 20 that is narrow at the top and wide at the bottom, and is L-shaped as a whole. The surface is provided with a water passage 22, and the upper body and the lower body of the body 20 are evenly spaced with drainage outlets, and the drainage outlets are connected with the L-shaped through-cavity; The side ditch 18 is connected to increase the drainage strength of the pavement structure.

The ecological curb structure 1 on the left and right sides in Fig. 1 is the cross-section of different parts of the overall structure respectively, the right side is the cross-section of the part of the structure connected with the rapids trough 17; the left side is the part of the structure not connected with the rapids trough 17 cross-section to increase drainage capacity.

The L-shaped through cavity includes the main drainage channel 27 in the stone wall cavity at the base and the auxiliary drainage channel 26 in the stone wall cavity at the curb. The cross sections of the main drainage channel 27 and the auxiliary drainage channel 26 are both rectangular, and they are connected to form a type through cavity.

The water passage 22 is a semi-cylindrical body (the cross section is arc-shaped) formed by the downward depression of the L-shaped corner along the height direction of the body 20. The two ends of the water passage 22 run through the length direction of the body 20 to prevent rainwater from collecting and causing Decreased soil strength leads to slope instability and failure.

Every interval of 15cm has a 5cm wide, 7.5cm high drain, the drain includes a high drain 21 and a low drain 23, the high drain 21 is arranged on the top of the curb, higher than the waterway 22; the low drain 23 The horizontal height is flush with the road surface structure, and each curb has a high-level drainage outlet 21 and a low-level drainage outlet 23. The high drain 21 is directly connected to the auxiliary drain 26 , the low drain 23 is directly connected to the main drain 27 , and every 10m is connected to a rapid trough 17 , and the rapid trough 17 communicates with the side ditch 18 . When there is little water on the road, the water level is relatively low, and the accumulated water flows from the road to the main drainage channel 27; At 23 o'clock, it flows to the auxiliary drainage channel 26 through the high-level drainage port 21, and the accumulated water is discharged to the side ditch 18 through the torrent trough 17. Water accumulated in the structure is removed.

The drains are arched, and the high drains 21 and the low drains 23 are equipped with arched trash traps, which are used to intercept fallen leaves, debris and soil in the green belt on the road surface, preventing a large amount of road garbage from flowing away from the polluted slope; The dirt net is detachable and easy to clean, and the pore size of the trash net is 5-20mm.

Each independent L-shaped curb stone is located on the exposed section 24 on the road surface with a length of 75cm, a width of 15cm, and a height of 10cm, and a length of the lower half of 75cm, width of 20cm, and height of 15cm. The embedding section 25 placed under the road surface is 10cm thick.

Because the pavement structure is too tight and the water seepage capacity of the pavement is not strong, the surface layer 3 of the pavement structure is provided with a 2% drainage cross slope, and the pavement water drains to the rapid flow groove 17 through the curb stone and finally flows into the side ditch 18, so as to ensure the resistance of the pavement to the bamboo whip. Under the action to achieve a certain drainage effect.

As shown in Figure 3, the subgrade of the subgrade slope structure is composed of an upper road bed 9, a lower road bed 10, an upper embankment 11, and a lower embankment 12. The first side slope filling layer 13, the second side slope filling layer 14, the second side slope filling layer The third side slope filling layer 15 and the fourth side slope filling layer 16 have different compaction degrees, follow the subgrade road surface compaction degree specification, the compaction degree of the upper road bed 9 is ≥94%, and the compaction degree of the lower road bed 10 is ≥ 94%, the compaction degree of the upper embankment 11≥93%, and the compaction degree of the lower embankment 12≥90%. The filling amount of remnant whip in the slope filling layer from bottom to top shows an increasing trend, and the filling amount increases by 2% for each layer, that is, the mass fraction of remnant whip filling from bottom to top is 8%, 10%, 12%, and 14%, respectively. The higher you go, the more tiny bamboo whips extend upwards through the gaps. At this time, it is necessary to increase the content of residual bamboo whips to resist the upward extension of bamboo whips by reducing the porosity of the soil and using the bamboo whips to avoid hardness.

In some embodiments, since the slope slope is 1:1.75, the filling amount of the soil layer is not the same for the shallow filling soil compaction degree of the slope, and the filling amount determined by the rolling test must be strictly controlled during the filling process of the roadbed. The degree of compaction can only be paved with new materials for the upper layer after the compaction is qualified. The places that cannot be compacted by mechanical compaction and the places where the compacted area is too small should be compacted with a small compactor, and after the filling is completed, the Fill the slope for shaping.

In some embodiments, layered edge wrapping or reinforcement is adopted for the shallow layer of the slope. In the subgrade slope structure, the excavated stones of the highway cutting or tunnel are crushed and filled on the outside of the subgrade slope to form the slope gravel layer A1. The purpose of hindering the growth of bamboo whips is achieved by embedding and compacting between the crushed stones; secondly, adding residual whips in the vegetation layer 19, the bamboo whips will avoid the hard characteristics that roots such as stumps will avoid, on the one hand, it can strengthen the bamboo whips on the other hand, it can play a reinforcing role, prevent the slope from collapsing, and at the same time reduce the impact of the atmospheric dry-wet cycle on the filler humidity. At the same time, the rapid flow trough 17 The water flow on the road surface can be collected to make it flow smoothly into the side ditch 18, which further improves the drainage efficiency of rainwater from the road surface, reduces the erosion of the rainwater on the road foundation slope, and enhances the stability of the slope.

While preparing concrete, the fiber bundles of high-strength fibers are uniformly mixed in the concrete, and the cementation of alicyclic epoxy resin and the filling properties of granular residual whips are added to obtain road pavement concrete and curbstones. The preparation material of the specimen has been greatly improved in terms of flexibility and strength. The concrete material has the advantages of low cost, convenient production, etc., and has the characteristics of better cohesion and compactness. The concrete is better than the traditional concrete. It is more durable and firm, and has stronger adaptability to the external environment, which greatly prolongs the service life of the pavement structure.

The high-strength fiber is made of polyacrylonitrile fiber, and the fiber diameter is 13 microns. It has high tensile strength, large initial modulus, and stable chemical properties. The fiber has acid and alkali corrosion resistance, light resistance, weather resistance, and has good dispersion. It can improve the cohesiveness and fatigue resistance of concrete, enhance the impermeability, frost resistance and impact resistance of concrete so that concrete can bear more load stress, and its bending toughness is more than 6 times higher than that of plain concrete; it has strong Excellent wear resistance and chemical corrosion resistance, and it can also maintain good mechanical properties under high-intensity exposure-rainfall and other dry-wet cycle conditions in outdoor environments.

Example 2,

A construction method for the control structure of the root swelling deformation of the subgrade road surface of the southern bamboo forest area. The specific steps are as follows:

S1. Pave the roadbed; carry out the side slope filling construction first, and clean up the surface of the site before filling. If there are multiple puddles on the ground surface, the accumulated water on the surface and the soil with excessive moisture content should be removed and replaced, and then backfilled to ensure that the road fill is dry, and then use a dump truck with an excavator, The bulldozer is combined with the whole to fill the soil, and the principle of rolling should be "thin filling, slow driving, and multiple times", and the rolling direction should be from the inside to the outside. Pay attention to overlapping and overlapping routes. During operation, the vibratory rolling machine should be more than 2.0m away from the edge of the fill to prevent the slope from toppling over. Among them, the layered compaction of the upper road bed 9, the lower road bed 10, the upper embankment 11, and the lower embankment 12 must be strictly The compaction parameters determined by the rolling test are controlled, and the new upper layer of new materials is allowed to be paved only after each layer of compaction is qualified. During the filling process, the filling shall strive to raise the entire section in parallel. When filling in sections, the joints of each layer shall be sloped at a ratio of 1:1.75, and the signs of rolling shall overlap by 1m. The upper and lower layers are staggered in sections, and the distance between the staggered joints is not less than 1m. On both sides of the subgrade, the fourth side slope filling layer 16 , the third side slope filling layer 15 , the second side slope filling layer 14 , and the first side slope filling layer 13 are filled sequentially from top to bottom.

S2. Lay the side slope gravel layer A1 on the outside of the subgrade side slope, use the road cutting or tunnel excavated stones to be filled and paved after crushing; hang the net on the side slope from top to bottom and from left to right The unwinding method is adopted, and the adjacent hanging nets on the same slope layer are bound with iron wires.

S3. After stirring the treated plant seeds with bamboo residue, gelling agent, water-retaining agent, nutrient fertilizer, and mud evenly, the mixture is evenly sprayed on the slope gravel layer A1 by a sprayer to form a vegetation layer 19. Ecological protection further prevents soil erosion. Mixed plant seeds are used for plant seeds. Tall fescue, bahia grass, and bermudagrass are mixed in a mass ratio of 4:5:1. A total of 30g of plant seeds are placed on a 1m ² slope, and the amount of bamboo residue is 30g/m ² . The dosage ratio of gelling agent, water retaining agent, nutrient fertilizer and mud per 0.1m ³ mixture is 0.05kg: 0.05kg: 0.15kg: 30kg.

Spraying is carried out twice, first spraying the mixture without seeds, spraying thickness 7-8cm, followed by spraying the mixture containing seeds for the second time, spraying thickness 2-3cm. The average thickness of the sprayed mixed material is 10cm, and the amplitude is 3-15cm; try to spray vertically on the slope, avoid spraying upwards, downwards or obliquely, and the spraying process should be repeated back and forth, and should not be sprayed at a certain point , to ensure uniform spraying thickness.

In the vegetation layer 19, insert 8-10 cm residual whips with intervals in the horizontal direction. The spacing range is 10-15 cm. The mass fraction of residual whips in the vegetation layer 19 is about 10% (9%-11%). Exceeding the corresponding range will destroy the vegetation. If the survival rate of plants in the layer is lower than the corresponding range, the residual whip cannot take defensive measures. Under the premise of being green and environmentally friendly, the bamboo whip can be used to "dodge" the residual whip and the gravel layer under the premise of being green and environmentally friendly.

S4. Lay the crushed stone cushion on the leveled embankment. The crushed stone base includes the lower base 7 and the upper base 6. The lower base 7 adopts 7% lime fly ash stabilized subbase, and the upper base 6 uses 5% lime powder. Coal ash stabilized gravel base, the thickness of the lower base 7 is 200mm, the thickness of the upper base 6 is 300mm, the thickness of the upper layer 4 is 40mm, and the thickness of the lower layer 5 is 60mm. The side slopes on both sides of the asphalt pavement structure 2 above the upper road bed 9 are filled with a roadside fill layer 8 .

The depth of the bamboo whip is generally more than 500mm underground, and the road surface compaction adopts rolling type, layered rolling, and the compaction degree is more than 95%. Single-layer compaction, compaction degree ≥ 96%, after the cement-stabilized gravel subbase is paved, maintenance and road surface control must be carried out. In the process of sprinkling water, the amount of water should be strictly controlled, and water soaking is strictly prohibited. The upper base layer 6 adopts concentrated mixing and is rolled in two layers, and the compaction degree is more than or equal to 98%. When the surface is slightly dry but not completely hardened, pour the permeable layer under the road and lay the asphalt lower seal in time. The degree of compaction of the upper base layer 6 is greater than 98%, and the degree of compaction of the lower base layer 7 is greater than 96%.

In order to make the connection between the surface layer and the base layer of the asphalt pavement structure 2 better, high-permeability emulsified asphalt is sprayed on the base layer. The permeable layer and the seal layer are made of PC-3 emulsified asphalt. Reach the depth of 5mm above the surface of the upper base layer. The penetration layer and the sealing layer play the role of transition, bonding and consolidation of the base layer surface. The use of emulsified asphalt reduces interlayer damage and plays a very important role in improving the durability of the road surface. effect. During the paving process, attention should be paid to the cleaning work between the layers to ensure that the layers are cleaned to prevent the soil from affecting the bonding between the layers. The modified emulsified asphalt adhesive layer can strengthen the bonding between the upper layer 4, the lower layer 5, the upper base layer 6, and the lower base layer 7, so that the adjacent surface layer and the base layer can be bonded into a firm whole to prevent mutual There is a phenomenon of sliding or pushing before the adjacent two layers, and in the pavement structure, in order to ensure the compactness of the pavement structure, its water permeability is not strong, and the use of modified emulsified asphalt adhesive layer for bonding can play a certain role in waterproofing .

Emulsified asphalt is a liquid asphalt that is produced by asphalt and emulsifier under a certain process; from the structure point of view, the emulsifier is composed of a non-polar hydrophobic group and a polar hydrophilic group. Affinity molecules, this structure makes the emulsifier form a directional and dense arrangement on the surface (interface) of the solution, changing the chemical properties of the surface (interface) of the system; it better solves the problem of asphalt flowing and oiling at high temperature, hard and brittle cracking at low temperature, etc. insufficient.

The surface of pavement structure surface layer 3 presents a certain inclination angle, and the inclination angle from inside to outside is 2% (i.e. drainage cross slope). Due to the tightness of the pavement structure, a certain inclination angle can increase the drainage capacity of the pavement.

S5. Ecological curb structure 1 is set on both sides of the road surface. If the foundation of ecological curb structure 1 is filled and excavated and rolled at the same time as the pavement base, the embedded section 25 of ecological curb structure 1 is buried under the road surface. Bamboo whips to resist; the exposed section 24 above the road surface is planed, leveled, and compacted according to the position flush with the road surface, and then installed, and an opening is set every 10m to connect the L-shaped through cavity inside the ecological curb structure 1 It is connected with the rush trough 17, and the rush trough 17 is arranged at intervals along the longitudinal direction of the road, and the rush trough 17 is connected with the side ditch 18 at the bottom of the slope, so that the water on the road surface can be easily removed.

Between the ecological curb structure 1 and the pavement structure, it is necessary to fill joints (prototype pointing). The raw material is prepared according to the bamboo whip aggregate ecological curb. The installation joint of the curb is 1cm, and it is hooked with 1:2 cement mortar Full and solid joints, saturation ≥ 80%, consistency 14-18s. When pointing, pay attention to protecting the curb from being polluted by mortar. You can first use plastic tape to glue the two sides of the joint of the curb and then start pointing. The curb should be firmly installed, the top surface is flat, and the seam is wide Uniform, dense pointing, smooth lines, to ensure that the exposed height is about 150mm.

Example 3,

Take by weighing 40 parts of the road cutting or tunnel excavation stone, 10 parts of calcium hydroxide, 10 parts of fly ash, 3 parts of bamboo and wood fiber, 10 parts of Portland cement, and 8 parts of alicyclic epoxy resin according to the following parts by weight. 5 parts, water 5 parts. Bamboo fiber is the remnant whip of moso bamboo with a length of 10mm.

The ecological curb structure 1 of the embodiment of the present invention uses local waste stone, calcium hydroxide, and fly ash as the base layer, and remnant whip fiber as the reinforced anti-compression material, and is pressed into the curb under the action of two-way high pressure.

Specific production method:

First, the bamboo and wood fiber (residual whip) and the road cutting or tunnel excavation stone are crushed, and the fine aggregate with a particle size of 0.075-2mm and the coarse aggregate with a particle size of 5-20mm are screened through different particle size sieves. , and sieve out impurities;

Weigh the excavated stone, calcium hydroxide, fly ash, bamboo and wood fiber, Portland cement, epoxy resin, water according to the corresponding parts by weight; send it into the mixer, stir for 6 minutes, and obtain the mixture;

Pour the stirred mixture into the curbstone model, and statically press it under 35-40 MPa bidirectional high pressure;

Naturally maintain the ecological curb stone formed by static pressure for 7-14 days.

Example 4,

Take by weighing 50 parts of the road cutting or tunnel excavation stone, 15 parts of calcium hydroxide, 12 parts of fly ash, 4 parts of bamboo and wood fiber, 13 parts of Portland cement, and 12 parts of cycloaliphatic epoxy resin according to the following parts by weight. 5 parts, 5 parts of water; Ecological curb structure 1 is prepared according to the method of embodiment 3, and the bamboo wood fiber is the residual whip of moso bamboo with a length of 10mm.

Example 5,

Take by weighing 70 parts of the road cutting or tunnel excavation stone, 20 parts of calcium hydroxide, 15 parts of fly ash, 5 parts of bamboo fiber, 16 parts of Portland cement, and 15 parts of cycloaliphatic epoxy resin according to the following parts by weight. 5 parts, 5 parts of water; Ecological curb structure 1 is prepared according to the method of embodiment 3; Bamboo wood fiber is the residual whip of moso bamboo with a length of 6mm.

Example 6,

Take by weighing 20 parts of the road cutting or tunnel excavation stone, 5 parts of calcium hydroxide, 8 parts of fly ash, 2 parts of bamboo fiber, 8 parts of Portland cement, 5 parts of cycloaliphatic epoxy resin according to the following parts by weight. 1 part, 1 part of water; ecological curb structure 1 is prepared according to the method of embodiment 3; the bamboo fiber is the residual whip of moso bamboo with a length of 8mm.

Comparative example 1,

The ecological curb does not contain bamboo fiber, cycloaliphatic epoxy resin, and calcium hydroxide in the raw materials, and the rest are the same as in Example 3.

The compressive and tensile strength test data of Examples 3-6 and Comparative Example 1 are shown in Table 1, and the drainage performance test data of Examples 3-6 and Comparative Example 1 are shown in Table 2, as shown in Figures 5 and 6.

Table 1 The mechanical performance test data of curb stone

Average compressive strength/MPa Average tensile strength/MPa Example 3 35.8 5.2 Example 4 36.4 4.9 Example 5 35.9 5.1 Example 6 36.2 5.0 Comparative example 1 32.1 4.3

Table 2 Drainage performance test data of curbs

Ecological curbstone structure 1 is made of environment-friendly materials, consisting of the following parts by weight: 20-70 parts of road cutting or tunnel excavation stone, 10-20 parts of calcium hydroxide, 8-15 parts of fly ash, 2-20 parts of bamboo and wood fiber 5 parts, 8-16 parts of Portland cement, 5-15 parts of alicyclic epoxy resin, 1-6 parts of water; among them, the bamboo wood fiber is the granular residual whip of moso bamboo to strengthen the road surface. The resistance ability, strengthen the compactness of the pavement structure, enhance the density of the pavement structure. Exceeding the corresponding range will damage the strength and service life of the curb; if the composition of raw materials exceeds the range, the concrete components of the prefabricated curb will not be formed; If the amount of sodium hydroxide added exceeds the corresponding range, it will corrode Portland cement and destroy the structure of the curb stone; if the amount of alicyclic epoxy resin added exceeds the corresponding range, the toughness of the curb stone will be reduced. It cracks easily.

In the embodiment, the curb fine aggregate is medium sand with a fineness modulus of 2.7 to 3.3 and a particle size of 0.075 to 2 mm; the coarse aggregate is selected from abandoned pavement panel construction waste with a maximum particle size of not more than 20 mm and a minimum particle size of not less than 5 mm As well as the road cutting or tunnel excavation stones, etc., saving costs and enhancing the strength of curbs. Fine aggregate and coarse aggregate together constitute excavation stone, and the mass ratio of fine aggregate to coarse aggregate is 5:1.

The proportion of fly ash is about 20%; it is mixed with 2-10mm remnant whip, choose the size of remnant whip within the appropriate range, grind the remnant whip in the natural state to make it segmented; the strength grade of cement is 42.5 Portland cement; the use of cycloaliphatic epoxy resin can enhance the gelation and bending resistance between concrete, not only has the characteristics of high adhesion, good mechanical properties of the cured product, and durability to temperature It is also very strong, whether it is in a high temperature environment or an ultra-low temperature environment, it has a high bond strength, which can improve the adhesion between high-strength special fibers and cement mortar and improve the adaptation of concrete components to outdoor temperature Residual whip particles as fillers can effectively fill the internal pores of concrete coarse and fine aggregates, reduce the porosity of concrete and the cracks and bending of concrete during use, and improve the flexibility of concrete components. It plays the role of skeleton and filling in the middle, increases stability, and plays a role in resisting root damage while reducing costs and saving environmental protection; (sodium hydroxide) is mixed with it to make curbs have good dry shrinkage performance, good freeze-thaw resistance, and anti-corrosion. It has strong mixing performance and reduces the creep of concrete. Road cuttings or tunnel excavation stones are used as coarse aggregates, bamboo and wood fibers (residual whip particles) are used as fillers, and in the case of pouring concrete, sodium hydroxide and cycloaliphatic epoxy resin are added to improve concrete components. Cooperate with each other to further enhance the strength of curb stone components, improve the compressive strength, and have strong durability to temperature, so as to resist cracks and bending of curb stones caused by temperature changes, and have strong drainage capacity.

In this embodiment, during the slope filling process, the road cutting or tunnel excavated stones are crushed and filled on the outside of the roadbed slope to form a slope gravel layer, and the purpose of hindering the growth of bamboo whips is achieved by embedding and compacting between the gravels. Secondly, adding the residual whip in the vegetation layer 19 plays the purpose of reinforcing the vegetation layer and suppressing the growth of the bamboo whip in the vegetation layer. While ensuring the reinforcing effect, it prevents the slope from collapsing and increases the slope Overall strength and action against roots. The rolling method and tamping method are used for slope filling. The rolling method is to use the pressure of mechanical rollers to compact the soil to achieve the required density; the tamping method is to use the impact force of the rammer to tamp the soil. , the soil pores are compressed, and the soil particles are arranged more tightly. The combination of the two methods makes the slope fill more compact and can resist the lateral growth of bamboo whips. So as to achieve the effect of resisting root damage.

Due to the characteristics of the horizontal growth of bamboo whips, the growth range is large. If concrete devices are used to consolidate the roots, it is difficult to protect them in all directions, the scope is too large, and the cost is greatly increased; Structure 2 and the subgrade slope structure are improved, and the three cooperate with each other and complement each other to form a harmonious and stable protection system, which enhances its strength without destroying the structural performance of the pavement, and resists the growth of bamboo whip roots through the gaps. At the same time, the circulation of accumulated water is increased, the drainage performance is improved, and the cost of construction can be reduced while providing comprehensive protection. In the embodiment of the present invention, by using the characteristics of bamboo whips "avoiding hard dives", by increasing the embedding depth of curb stones and the thickness of pavement structure, and reducing the porosity (4-6%) of pavement structure layer, thereby changing the extension direction, through root The bulging deformation is regulated to control the downward bending growth of the bamboo whip.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A root swelling deformation control structure of the road subgrade pavement in the South Bamboo Forest District, is characterized in that, comprising: An asphalt pavement structure (2), the thickness of the asphalt pavement structure matches the depth of bamboo whips growing underground, and the surface layer (3) of the pavement structure is provided with a drainage transverse slope; An ecological curb structure (1), the ecological curb structure (1) includes a body (20) that is narrow at the top and wide at the bottom, and is generally L-shaped. The body (20) is provided with an L-shaped through cavity inside, and the body (20) ) is provided with a water channel (22) on the upper surface of the lower body, and the two ends of the water channel (22) run through along the length direction of the body (20); The L-shaped through cavity is connected, and the L-shaped through cavity is connected with the side ditch (18) at the bottom of the slope through the rush trough (17) arranged at intervals along the longitudinal direction of the road; The embankment side slope structure, wherein the amount of remnant whip filling in the side slope filling layer of the roadbed side slope structure gradually increases from bottom to top. 2. According to claim 1, a structure for regulating and controlling the root swelling deformation of roadbed and pavement in the southern bamboo forest area, is characterized in that, the raw materials of the ecological curb structure (1) are composed of the following parts by weight: 20-70 parts of excavated stone , 10~20 parts of calcium hydroxide, 8~15 parts of fly ash, 2~5 parts of bamboo and wood fiber, 8~16 parts of Portland cement, 5~15 parts of alicyclic epoxy resin, 1~6 parts of water Parts; Among them, the bamboo wood fiber is the granular residual whip of moso bamboo. 3. According to claim 1, a control structure for root swelling deformation of road subgrade pavement in southern bamboo forest area, characterized in that, the asphalt pavement structure (2) adopts a skeleton-dense structure with a porosity of 4-6%. 4. According to claim 1, a control structure for root swelling deformation of highway subgrade pavement in southern bamboo forest area, characterized in that, the asphalt pavement structure (2) sequentially includes a lower base (7) and an upper base (6) from bottom to top , the lower layer (5), the upper layer (4), the lower base layer (7) uses lime fly ash stabilized base, the upper base (6) uses lime fly ash stabilized sand and gravel base, and the lower layer (5) adopts medium-grained modified asphalt concrete; the upper layer (4) adopts fine-grained modified asphalt concrete; between the upper layer (4) and the lower layer (5), and between the lower layer (5) and the upper base layer (6) are emulsified by modification Asphalt adhesive layer for bonding. 5. According to claim 1, a control structure for root bulge deformation of highway subgrade and pavement in southern bamboo forest area, characterized in that, the water passage (22) is formed by a downward depression at an L-shaped corner along the height direction of the body (20) , the section is arc-shaped. 6. According to claim 1, a control structure for controlling root swelling deformation of road subgrade road surface in southern bamboo forest area, characterized in that, the drainage outlets include high-level drainage outlets (21) and low-level drainage outlets (23), and the high-level drainage outlets (21 ) is arranged on the upper part of the body (20), higher than the water passage (22); the level of the low drain outlet (23) is flush with the road surface structure, and the interval between the drain outlets is 15-20cm. 7. according to claim 1, a kind of south bamboo forest area highway subgrade pavement root swelling control structure, it is characterized in that, described outfall is arch type, and outfall is provided with arch type trash-stop, and the aperture of trash-block is 5~20mm. 8. According to claim 1, a control structure for root swelling deformation of road subgrade road surface in southern bamboo forest area, characterized in that, the subgrade of the subgrade slope structure includes a lower embankment (12) and an upper embankment (11) from bottom to top. , the lower road bed (10), the upper road bed (9), the side slopes on both sides of the asphalt pavement structure (2) above the upper road bed (9) are filled with roadside fill layers (8); the side slopes on both sides of the road bed From bottom to top, it includes the fourth side slope filling layer (16), the third side slope filling layer (15), the second side slope filling layer (14), the first side slope filling layer (13), the slope The mass fraction of remnants added to the filling layer is 8%~14%, showing an increasing trend from bottom to top. 9. According to claim 1, a control structure for root swelling deformation of roadbed road surface in southern bamboo forest area, characterized in that, the slope surface of the roadbed slope structure is provided with a slope gravel layer and a vegetation layer (19) in sequence , in the vegetation layer (19) there are intervals in the inner lateral direction to insert remnant whips with a length of 8-10 cm, and the mass fraction of remnant whips added is 9%-11%. 10. the construction method of a kind of southern bamboo forest district highway subgrade pavement root swelling deformation regulation and control structure as claimed in claim 1, is characterized in that, comprises the following steps: S1, pave the roadbed; S2. Lay a slope gravel layer on the outside of the roadbed slope, and hang a net on the slope; S3, spraying the vegetation layer (19) on the slope gravel layer; S4. Lay the asphalt pavement structure (2) on the leveled roadbed, and the surface layer of the pavement structure (3) is provided with a drainage cross slope; S5. Set up ecological curb structures (1) on both sides of the road surface. The embedded section (25) of the ecological curb stone structure (1) is buried under the road surface, and the exposed section (24) above the road surface is flush with the road surface. After planing, leveling, and tamping the position, install an opening every 10-15m to connect the L-shaped through cavity inside the ecological curb structure (1) with the rapids trough (17), and the rapids trough (17) along the The road is longitudinally arranged at intervals, and the rapid flow trough (17) is connected with the side ditch (18) at the bottom of the slope; joints are filled between the ecological curb structure (1) and the pavement structure.

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