CN109881660B - A construction method for scour protection of marine building foundations combined with microbial solidification and anti-seepage wall - Google Patents
A construction method for scour protection of marine building foundations combined with microbial solidification and anti-seepage wall Download PDFInfo
- Publication number
- CN109881660B CN109881660B CN201910136348.6A CN201910136348A CN109881660B CN 109881660 B CN109881660 B CN 109881660B CN 201910136348 A CN201910136348 A CN 201910136348A CN 109881660 B CN109881660 B CN 109881660B
- Authority
- CN
- China
- Prior art keywords
- grouting
- seepage wall
- seepage
- foundation
- cover plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000010276 construction Methods 0.000 title claims abstract description 33
- 238000007711 solidification Methods 0.000 title claims abstract description 17
- 230000008023 solidification Effects 0.000 title claims abstract description 17
- 230000000813 microbial effect Effects 0.000 title claims abstract description 12
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 53
- 239000010959 steel Substances 0.000 claims abstract description 53
- 238000000034 method Methods 0.000 claims abstract description 38
- 239000002689 soil Substances 0.000 claims abstract description 35
- 239000004576 sand Substances 0.000 claims abstract description 32
- 238000002347 injection Methods 0.000 claims abstract description 26
- 239000007924 injection Substances 0.000 claims abstract description 26
- 239000013505 freshwater Substances 0.000 claims abstract description 23
- 238000006243 chemical reaction Methods 0.000 claims abstract description 18
- 239000013535 sea water Substances 0.000 claims abstract description 13
- 101000965313 Legionella pneumophila subsp. pneumophila (strain Philadelphia 1 / ATCC 33152 / DSM 7513) Aconitate hydratase A Proteins 0.000 claims abstract 3
- 239000007788 liquid Substances 0.000 claims description 34
- 241000894006 Bacteria Species 0.000 claims description 26
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 26
- 239000000243 solution Substances 0.000 claims description 19
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 18
- 239000011259 mixed solution Substances 0.000 claims description 18
- 244000005700 microbiome Species 0.000 claims description 15
- 238000007789 sealing Methods 0.000 claims description 15
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 13
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 12
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 12
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 12
- 239000001110 calcium chloride Substances 0.000 claims description 12
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 12
- 239000004202 carbamide Substances 0.000 claims description 12
- 150000007522 mineralic acids Chemical class 0.000 claims description 12
- 150000007524 organic acids Chemical class 0.000 claims description 12
- 230000000694 effects Effects 0.000 claims description 11
- 229920001971 elastomer Polymers 0.000 claims description 11
- 238000009434 installation Methods 0.000 claims description 11
- 239000011148 porous material Substances 0.000 claims description 11
- 230000008569 process Effects 0.000 claims description 11
- 108010046334 Urease Proteins 0.000 claims description 8
- 230000001580 bacterial effect Effects 0.000 claims description 8
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 6
- 229910017604 nitric acid Inorganic materials 0.000 claims description 6
- 230000003068 static effect Effects 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 5
- 241000606860 Pasteurella Species 0.000 claims description 4
- 238000001556 precipitation Methods 0.000 claims description 4
- 241000193830 Bacillus <bacterium> Species 0.000 claims 2
- 239000000203 mixture Substances 0.000 claims 2
- 230000035515 penetration Effects 0.000 claims 1
- 238000009751 slip forming Methods 0.000 claims 1
- 238000005516 engineering process Methods 0.000 abstract description 6
- 238000009991 scouring Methods 0.000 description 12
- 239000002244 precipitate Substances 0.000 description 8
- 230000000149 penetrating effect Effects 0.000 description 4
- 235000014653 Carica parviflora Nutrition 0.000 description 3
- 241000243321 Cnidaria Species 0.000 description 3
- 241000193469 Clostridium pasteurianum Species 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000002787 reinforcement Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000005429 filling process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
Images
Landscapes
- Bulkheads Adapted To Foundation Construction (AREA)
- Revetment (AREA)
Abstract
本发明涉及一种微生物固化联合防渗墙的海工建筑物基础冲刷防护施工方法，主要步骤为在海工建筑物基础周围安装防渗墙，并在防渗墙顶部添加盖板，通过盖板顶部的注浆孔在防渗墙区域内部由上而下注入淡水，形成适宜的MICP反应环境，采用低pH一相注的方法对防渗墙区域内部进行注浆，反复注浆多次，直至微生物固化形成的砂土抗冲刷强度达到设计要求为止；本发明克服了MICP技术应用于海水环境中的不确定性，形成的固化土层强度均匀，施工简便且防渗墙由T型钢板桩装配形成，易于安装和拆除，操作灵活性大，可对诸如海上风机、防波堤、海上石油平台等多种海工建筑物基础进行冲刷防护，且对海洋环境基本无污染，应用前景广阔。
The invention relates to a construction method for protecting the foundation of marine buildings by microbial curing combined with anti-seepage walls. The main steps include installing anti-seepage walls around the foundations of marine buildings, adding a cover plate on the top of the anti-seepage wall, and passing the cover plate. The grouting hole at the top is injected with fresh water from top to bottom in the anti-seepage wall area to form a suitable MICP reaction environment. The low pH one-phase injection method is used to grouting the inside of the anti-seepage wall area, and the grouting is repeated several times until The anti-scour strength of the sand formed by microbial solidification reaches the design requirements; the invention overcomes the uncertainty of the application of the MICP technology in the seawater environment, the formed solidified soil layer has uniform strength, is easy to construct, and the anti-seepage wall is assembled by T-shaped steel sheet piles It is easy to install and dismantle, and has great operational flexibility. It can protect the foundations of various offshore structures such as offshore wind turbines, breakwaters, and offshore oil platforms. It is basically pollution-free to the marine environment and has broad application prospects.
Description
Technical Field
The invention relates to a scouring protection construction method for a marine structure foundation by combining microorganism solidification with an impervious wall, and belongs to the field of scouring protection of the building foundation.
Background
In recent years, with the development of cross-studies between disciplines such as microbial chemistry and civil engineering, the technique of microbial-induced calcium carbonate deposition (MICP) has been increasingly applied to various related fields. Such as sewage treatment, desert dust control, concrete restoration and the like, and is also widely applied to the improvement of the strength and stability of foundation soil. In the research at home and abroad, the MICP mechanism under the condition of fresh water is well known, but the research on the MICP reaction process under the condition of seawater is still in the initial stage. Therefore, how the effect of MICP to treat weak foundation soil in a seawater environment is not known, which also becomes a great problem in the field of the application of MICP technology to ocean engineering.
The prior patent No. 201711277952.8 discloses a coral sand stratum barrel-shaped foundation reinforcing device and an installation method based on MICP, the method adopts a two-phase injection MICP grouting technology to carry out grouting reinforcement on a coral sand stratum in a barrel-shaped foundation, thereby increasing the bearing capacity and stability of the coral sand stratum; there is also a large diameter pile foundation anti-scouring method and apparatus based on MICP technology of patent No. 201810283744.7, through the MICP of two-phase pouring, pump circulation, form the seepage field around the pile foundation, and then strengthen the soil body around the marine pile foundation and achieve the effect of anti-scouring; and a microbe sand pile forming device and method with patent number 201710138458.7, which injects the mixed liquid of bacteria and cementing liquid into the sand inside the cylinder by a phase-injection MICP grouting technique, thereby achieving the purpose of forming piles in island reefs and desert areas. The method has certain defects that the limitation and influence of pore seawater in sea-based saturated sandy soil on the grouting process under the actual condition are not considered in the grouting process, so that the process has certain limitations. Meanwhile, when the grouting liquid is applied to a seawater environment, uncertainty is still provided on the success of the sand cementation. Moreover, the grouting methods adopted in the MICP process of the above patents are two-phase grouting or one-phase grouting. The two-phase injection is to inject the microorganism urease bacteria firstly and then inject the mineralized liquid. The grouting process has proved that the uniformity of the processing result is difficult to ensure when processing large-scale soil mass, so that the strength uniformity of the formed calcified soil mass is difficult to ensure after grouting; the one-phase injection refers to that the microorganism urease bacteria and the mineralized liquid are mixed and then injected simultaneously, and a large amount of calcium carbonate precipitates are formed in the early stage of the injection to block an injection port, so that the one-phase injection is generally not recommended to be used.
Based on the two defects, a new scouring protection construction method for the marine building foundation of the microbial curing combined impervious wall is urgently needed to be provided, the MICP technology is carried out in the marine environment, so that the scouring protection construction method is simple to operate, high in mounting and dismounting flexibility during construction, capable of scouring and protecting various marine building foundations, and good in uniformity of the strength of the formed cured soil layer.
Disclosure of Invention
The invention provides a marine building foundation scouring protection construction method of a microbial curing combined impervious wall, which has the characteristics of simple construction, high operation flexibility, no blockage of a grouting port during grouting, stable formed consolidated soil effect, one-time effect after protection, no need of repair and maintenance for many times and environmental friendliness.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a scouring protection construction method for marine structure foundation of microorganism curing combined impervious wall comprises the following steps:
the first step is as follows: prefabricating at least eight T-shaped steel sheet piles and cover plates, arranging two lifting holes on a vertical column part of each T-shaped steel sheet pile, enabling the penetrating direction of each lifting hole to be parallel to the horizontal plane of each T-shaped steel sheet pile, enabling the distance between each lifting hole and the horizontal plane of each T-shaped steel sheet pile to be 40cm, and uniformly distributing at least eight grouting holes with threads on the surfaces of the cover plates;
the second step is that: sinking the T-shaped steel sheet piles around the marine structure foundation by a static pressure or hammering method, wherein two adjacent T-shaped steel sheet piles form a connection mode of forward installation and backward installation, a closed impervious wall is formed around the marine structure foundation by sequentially connecting at least eight T-shaped steel sheet piles, and the top of the formed impervious wall is higher than the surface of the marine bed;
the third step: leveling the surface of the sea bed in the forming area in the impervious wall, simultaneously collecting sand samples in the construction area in the impervious wall, and measuring the porosity of the sand samples to obtain the pore volume of sand and soil in the impervious wall;
the fourth step: the cover plate is arranged at an opening of an area formed by the closed impervious wall, a grouting hole in the cover plate is connected with one end of a grouting pipe in a sealing mode through threads, the other end of the grouting pipe is connected with the other grouting pipes in a lap joint mode to form a connector and then is connected with the grouting main pipe, and the contact part of the cover plate and the impervious wall is sealed through a rubber sealing strip;
the fifth step: fresh water is injected into the impervious wall area from the top of the impervious wall, the volume of the injected fresh water is 1.2-1.4 times of the pore volume of the sand soil in the impervious wall, and seawater in the impervious wall area is discharged, so that a fresh water environment suitable for MICP reaction is formed;
and a sixth step: injecting a prepared mixed solution of bacteria and a cementing solution into the interior of the impervious wall area from top to bottom by adopting a low-pH one-phase injection method, waiting for 12-24 hours until the reaction is fully carried out, and continuously generating calcium carbonate precipitates among sand and soil particles during the reaction;
the seventh step: repeating the sixth step until the impact strength of the sandy soil formed by the microorganism solidification reaches a preset value;
eighth step: inserting a lifting appliance into the grouting hole, removing a cover plate covered at an opening of an area formed by the impervious wall, then inserting the lifting appliance into the lifting hole, removing the T-shaped steel sheet pile forming the impervious wall, and finally forming a solidified soil layer with impact resistance in the protection area;
as a further preferred aspect of the present invention, in the pile sinking process of the T-shaped steel sheet pile, a section of guide wall is arranged at an initial point of the pile sinking, an impervious wall formed by the pile sinking surrounds the exterior of the foundation of the marine structure, and the shape surrounded by the impervious wall is square;
as a further preferred aspect of the present invention, the shape of the aforementioned cover plate is fitted with the shape of the opening of the enclosed impervious wall; digging a hole in the center of the cover plate, wherein the hole shape of the hole is matched with the shape of the foundation of the marine building;
as a further preferred aspect of the present invention, the cover plate is manufactured by dividing the cover plate into two identical parts along the central line thereof, during construction, the cover plate is folded at the bottom of the marine building foundation, the folded and contacted parts are sealed by rubber sealing strips, the cover plate, the impervious wall and the marine building foundation form a closed structure, and the bottom of the formed closed structure is hollow;
in a further preferred embodiment of the present invention, the diameter of the injection hole is 4cm,
when the marine structure foundation is in a circular shape, at least eight grouting holes are formed along the circumference of the marine structure foundation by taking the center of the cover plate as the center of a circle, and the included angle between every two adjacent grouting holes is 45 degrees;
when the marine building foundation is in a square structure, grouting holes are formed along the side line of the marine building foundation, and the distance between every two adjacent grouting holes is 1 m;
as a further preferred mode of the invention, the prepared mixed solution of the bacteria and the cementing solution is injected into the interior of the impervious wall area from top to bottom, the bacteria adopt bacillus pasteurianus, and the urease activity is 1.5-20U/mL; the cementing solution adopts 0.1-2mol/L mixed solution of calcium chloride and urea, and the concentration ratio of the calcium chloride to the urea is 1: 1;
as a further preferred aspect of the invention, a mixed solution of prepared bacteria and a cementing solution is injected into the interior of the impervious wall region from top to bottom, wherein the bacteria adopt bacillus pasteurianus, and the urease activity is 10U/mL; the cementing solution adopts 1.5mol/L mixed solution of calcium chloride and urea, and the concentration ratio of the calcium chloride to the urea is 1: 1;
as a further preferred aspect of the present invention: the injection method adopting low pH one-phase injection specifically comprises the following steps:
step 6 a: adjusting the pH value of the bacterial liquid to 4-5 by adopting 0.25-4mol/L of organic acid or inorganic acid, namely hydrochloric acid, acetic acid or nitric acid;
step 6 b: adding the cementing liquid in equal volume, and adjusting the final pH value of the mixed liquid of the bacteria liquid and the cementing liquid to 3.5-4.5 by using the organic acid and the inorganic acid; the low pH can effectively obtain homogeneous mixed liquor in a certain window period;
step 6 c: grouting the interior of the diaphragm wall area at a grouting rate of 1-10L/min, and completing grouting work in a window period when calcium carbonate precipitation is not generated in mixed liquid of bacteria and cementing liquid;
as a further preferred aspect of the present invention, the injection method using low pH one-phase injection specifically comprises the following steps:
step 6 a: adjusting the pH value of the bacterial liquid to 4-5 by adopting 2mol/L organic acid or inorganic acid, namely hydrochloric acid, acetic acid or nitric acid;
step 6 b: adding the cementing liquid in the same volume, and adjusting the final pH value of the mixed liquid of the bacteria liquid and the cementing liquid to 4 by using the organic acid and the inorganic acid; the low pH can effectively obtain homogeneous mixed liquor in a certain window period;
step 6 c: and grouting the inner part of the impervious wall area at a grouting speed of 1-10L/min, and finishing grouting in a window period when the mixed solution of bacteria and the cementing solution does not generate calcium carbonate precipitate.
Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:
(1) by adopting the method of injecting fresh water into the closed area, the microorganism induced MICP process can be prevented from being influenced by high salinity of seawater and internal seepage of sandy soil, and an environment-controllable MICP reaction area is formed, so that the MICP technology commonly used for urban rock and soil reinforcement can be well applied to the marine environment;
(2) compared with the traditional one-phase injection and two-phase injection methods, the low-pH one-phase injection grouting method is simpler, does not block a grouting opening, and ensures that the strength of the foundation soil formed by solidification is more uniform;
(3) the construction method adopts the assembled T-shaped steel sheet pile to form the impervious wall, is easy to install and dismantle, and can be repeatedly used;
(4) the construction method has great flexibility and wide application, and can be used for scouring and protecting the foundations of various marine structures such as offshore wind turbines, breakwaters, offshore oil platforms and the like;
(5) compared with the traditional method (stone throwing protection and the like), the construction method has better protection effect, does not need to carry out multiple protection, has good ecological property and basically does not cause pollution to the marine environment.
Drawings
The invention is further illustrated with reference to the following figures and examples.
Fig. 1 is three views of a T-shaped steel sheet pile according to a preferred embodiment of the present invention, wherein 1a is a front view, 1b is a left view, and 1c is a top view;
FIG. 2 is an elevational view of the assembled form of a T-shaped steel sheet pile and a cover plate according to the preferred embodiment of the present invention;
FIG. 3 is a sectional view of a portion A-A in an elevation view of an assembled form of a T-shaped steel sheet pile and a cover plate according to a preferred embodiment of the present invention;
fig. 4 is a construction flow chart of the cutoff wall according to the preferred embodiment of the present invention;
FIG. 5 is a schematic illustration of a grouting process of a preferred embodiment of the invention;
FIG. 6 is a schematic diagram of the diaphragm wall shape and the grouting hole position when the marine structure foundation is in a circular shape in the preferred embodiment of the present invention;
fig. 7 is a schematic diagram showing the shape of the diaphragm wall and the position of the grouting holes when the marine structure foundation is in a square shape in the preferred embodiment of the present invention.
In the figure: the construction method comprises the following steps of 1, 2, a cover plate, 3, a rubber sealing strip, 4, a hanging hole, 5, a grouting hole, 6, a grouting pipe, 7, a grouting main pipe, 8, a solidified soil layer and 9, wherein the T-shaped steel sheet pile, the cover plate, the rubber sealing strip, the grouting hole, the grouting main pipe, the solidified soil layer and the impervious wall are arranged in sequence.
Detailed Description
The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.
As shown in fig. 1-7, the present invention includes the following features: the construction method comprises the following steps of 1, 2, a cover plate, 3, a rubber sealing strip, 4, a hanging hole, 5, a grouting hole, 6, a grouting pipe, 7, a grouting main pipe, 9, an impervious wall and 8, wherein the T-shaped steel sheet pile, the cover plate, the rubber sealing strip, the hanging hole, the grouting main pipe and the impervious wall are arranged in sequence.
The invention relates to a scouring protection construction method for a marine building foundation of a microbial curing combined impervious wall, which comprises the following steps of:
the first step is as follows: prefabricating at least eight T-shaped steel sheet piles and cover plates, arranging two lifting holes on a vertical column part of each T-shaped steel sheet pile, enabling the penetrating direction of each lifting hole to be parallel to the horizontal plane of each T-shaped steel sheet pile, enabling the distance between each lifting hole and the horizontal plane of each T-shaped steel sheet pile to be 40cm, and uniformly distributing at least eight grouting holes with threads on the surfaces of the cover plates;
the second step is that: sinking the T-shaped steel sheet piles around the marine structure foundation by a static pressure or hammering method, wherein two adjacent T-shaped steel sheet piles form a connection mode of forward installation and backward installation, a closed impervious wall is formed around the marine structure foundation by sequentially connecting at least eight T-shaped steel sheet piles, and the top of the formed impervious wall is higher than the surface of the marine bed;
the third step: leveling the surface of the sea bed in the forming area in the impervious wall, simultaneously collecting sand samples in the construction area in the impervious wall, and measuring the porosity of the sand samples to obtain the pore volume of sand and soil in the impervious wall;
the fourth step: the cover plate is arranged at an opening of an area formed by the closed impervious wall, a grouting hole in the cover plate is connected with one end of a grouting pipe in a sealing mode through threads, the other end of the grouting pipe is connected with the other grouting pipes in a lap joint mode to form a connector and then is connected with the grouting main pipe, and the contact part of the cover plate and the impervious wall is sealed through a rubber sealing strip;
the fifth step: fresh water is injected into the impervious wall area from the top of the impervious wall, the volume of the injected fresh water is 1.2-1.4 times of the pore volume of the sand soil in the impervious wall, and seawater in the impervious wall area is discharged, so that a fresh water environment suitable for MICP reaction is formed;
and a sixth step: injecting a prepared mixed solution of bacteria and a cementing solution into the interior of the impervious wall area from top to bottom by adopting a low-pH one-phase injection method, waiting for 12-24 hours until the reaction is fully carried out, and continuously generating calcium carbonate precipitates among sand and soil particles during the reaction;
the seventh step: repeating the sixth step until the impact strength of the sandy soil formed by the microorganism solidification reaches a preset value;
eighth step: and inserting a lifting appliance into the grouting hole, removing the cover plate covering the opening of the region formed by the impervious wall, then inserting the lifting appliance into the lifting hole, removing the T-shaped steel sheet pile forming the impervious wall, and finally forming a solidified soil layer with impact resistance in the protection region.
Fig. 1, 2, 3, 4, 5 and 6 show a first embodiment of the present invention, that is, when the marine structure foundation is in a circular shape,
as shown in fig. 4, the first step: prefabricating a T-shaped steel sheet pile and a cover plate in a factory; prefabricating a plurality of T-shaped steel sheet piles and a cover plate, arranging two lifting holes on a vertical column part of each T-shaped steel sheet pile, enabling the penetrating direction of the lifting holes to be parallel to the horizontal plane of each T-shaped steel sheet pile, enabling the distance between each lifting hole and the horizontal plane of each T-shaped steel sheet pile to be 40cm till now, and arranging at least eight grouting holes on the surface of the cover plate by taking the center of the cover plate as the center of a circle and enabling two adjacent grouting holes to form a 45-degree included angle as shown in figure 6;
the second step is that: pile sinking construction; sinking the T-shaped steel sheet piles around the marine structure foundation by a static pressure or hammering method, wherein two adjacent T-shaped steel sheet piles form a connection mode of forward installation and backward installation, a closed impervious wall is formed around the marine structure foundation through the sequential connection of a plurality of T-shaped steel sheet piles, and the top of the formed impervious wall is higher than the surface of the marine bed;
the third step: leveling and sampling; leveling the surface of the sea bed in the forming area in the impervious wall, simultaneously collecting sand samples in the construction area in the impervious wall, and measuring the porosity of the sand samples to obtain the pore volume of sand and soil in the impervious wall;
the fourth step: the grouting pipe is connected and installed with the cover plate; the cover plate is divided into two identical parts along the central line of the cover plate to be manufactured, the cover plate is folded at the bottom of the marine building foundation, a grouting hole in the cover plate is connected with one end of a grouting pipe in a sealing mode through threads, the other end of the grouting pipe is connected with a grouting main pipe after being lapped with other grouting pipes to form an interface, the folded and contacted part is sealed through a rubber sealing strip, the cover plate, the impervious wall and the marine building foundation form a closed structure, and the bottom of the formed closed structure is hollow;
the fifth step: filling fresh water; fresh water is injected into the impervious wall area from the top of the impervious wall, the volume of the injected fresh water is 1.2-1.4 times of the pore volume of the sand soil in the impervious wall, and seawater in the impervious wall area is discharged, so that a fresh water environment suitable for MICP reaction is formed;
and a sixth step: grouting; adjusting the pH of the bacterial liquid to 4-5 by adopting a low-pH one-phase injection method and 2mol/L organic acid or inorganic acid, namely hydrochloric acid, acetic acid or nitric acid, wherein the bacteria adopt pasteurella, and the urease activity is 10U/mL;
adding a cementing solution with the same volume, wherein the cementing solution is a mixed solution of 1.5mol/L of calcium chloride and urea, and the concentration ratio of the calcium chloride to the urea is 1: 1, adjusting the final pH value of the mixed liquid of the bacteria liquid and the cementing liquid to 4 by using the organic acid and the inorganic acid; the low pH can effectively obtain homogeneous mixed liquor in a certain window period;
grouting the interior of the impervious wall area at a grouting rate of 1-10L/min, completing grouting work in a window period when the mixed solution of bacteria and cementing liquid does not generate calcium carbonate precipitates, waiting for 12-24 hours until the reaction is fully performed, and continuously generating calcium carbonate precipitates among sand and soil particles during the reaction period;
the seventh step: repeating the sixth step until the impact strength of the sandy soil formed by the microorganism solidification reaches a preset value;
eighth step: removing the mold; and inserting a lifting appliance into the grouting hole, removing the cover plate covering the opening of the region formed by the impervious wall, then inserting the lifting appliance into the lifting hole, removing the T-shaped steel sheet pile forming the impervious wall, and finally forming a solidified soil layer with impact resistance in the protection region.
Fig. 1, 2, 3, 4, 5 and 7 show a second embodiment of the present invention, that is, when the marine structure foundation is a square structure,
as shown in fig. 4, the first step: prefabricating a T-shaped steel sheet pile and a cover plate in a factory; prefabricating a plurality of T-shaped steel sheet piles and a cover plate, arranging two lifting holes on a vertical column part of each T-shaped steel sheet pile, enabling the penetrating direction of the lifting holes to be parallel to the horizontal plane of each T-shaped steel sheet pile, enabling the distance between each lifting hole and the horizontal plane of each T-shaped steel sheet pile to be 40cm till now, arranging at least eight grouting holes on the surface of the cover plate, and enabling the distance between every two adjacent grouting holes to be 1m as shown in fig. 7;
the second step is that: pile sinking; sinking the T-shaped steel sheet piles around the marine structure foundation by a static pressure or hammering method, wherein two adjacent T-shaped steel sheet piles form a connection mode of forward installation and backward installation, a closed impervious wall is formed around the marine structure foundation through the sequential connection of a plurality of T-shaped steel sheet piles, and the top of the formed impervious wall is higher than the surface of the marine bed;
the third step: leveling and sampling; leveling the surface of the sea bed in the forming area in the impervious wall, simultaneously collecting sand samples in the construction area in the impervious wall, and measuring the porosity of the sand samples to obtain the pore volume of sand and soil in the impervious wall;
the fourth step: connecting grouting pipes and installing cover plates; the cover plate is divided into two identical parts along the central line of the cover plate to be manufactured, the cover plate is folded at the bottom of the marine building foundation, a grouting hole in the cover plate is connected with one end of a grouting pipe in a sealing mode through threads, the other end of the grouting pipe is connected with a grouting main pipe after being lapped with other grouting pipes to form an interface, the folded and contacted part is sealed through a rubber sealing strip, the cover plate, the impervious wall and the marine building foundation form a closed structure, and the bottom of the formed closed structure is hollow;
the fifth step: filling fresh water; fresh water is injected into the impervious wall area from the top of the impervious wall, the volume of the injected fresh water is 1.2-1.4 times of the pore volume of the sand soil in the impervious wall, and seawater in the impervious wall area is discharged, so that a fresh water environment suitable for MICP reaction is formed;
and a sixth step: grouting; adjusting the pH of the bacterial liquid to 4-5 by adopting a low-pH one-phase injection method and 2mol/L organic acid or inorganic acid, namely hydrochloric acid, acetic acid or nitric acid, wherein the bacteria adopt pasteurella, and the urease activity is 10U/mL;
adding a cementing solution with the same volume, wherein the cementing solution is a mixed solution of 1.5mol/L of calcium chloride and urea, and the concentration ratio of the calcium chloride to the urea is 1: 1, adjusting the final pH value of the mixed liquid of the bacteria liquid and the cementing liquid to 4 by using the organic acid and the inorganic acid; the low pH can effectively obtain homogeneous mixed liquor in a certain window period;
grouting the interior of the impervious wall area at a grouting rate of 1-10L/min, completing grouting work in a window period when the mixed solution of bacteria and cementing liquid does not generate calcium carbonate precipitates, waiting for 12-24 hours until the reaction is fully performed, and continuously generating calcium carbonate precipitates among sand and soil particles during the reaction period;
the seventh step: repeating the sixth step until the impact strength of the sandy soil formed by the microorganism solidification reaches a preset value;
eighth step: removing the mold; and inserting a lifting appliance into the grouting hole, removing the cover plate covering the opening of the region formed by the impervious wall, then inserting the lifting appliance into the lifting hole, removing the T-shaped steel sheet pile forming the impervious wall, and finally forming a solidified soil layer with impact resistance in the protection region.
In the embodiment, in the pile sinking process, the pile sinking of the T-shaped steel sheet piles is carried out around the pile foundation in a static pressure or hammering mode, the pile sinking process strictly meets related technical specifications, a T-shaped and inverted T-shaped connection mode is formed among each T-shaped steel sheet pile, finally, the pile foundation is assembled to form a closed impervious wall, all the impervious walls are buried, and the top of the impervious wall is exposed out of the surface of the sea bed;
in the fresh water filling process, the principle that the density of the fresh water is smaller than that of the sea water is utilized to discharge the sea water in the impervious wall area, so that a fresh water environment suitable for MICP reaction is formed in the impervious wall area.
It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The meaning of "and/or" as used herein is intended to include both the individual components or both.
The term "connected" as used herein may mean either a direct connection between components or an indirect connection between components via other components.
In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910136348.6A CN109881660B (en) | 2019-02-25 | 2019-02-25 | A construction method for scour protection of marine building foundations combined with microbial solidification and anti-seepage wall |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910136348.6A CN109881660B (en) | 2019-02-25 | 2019-02-25 | A construction method for scour protection of marine building foundations combined with microbial solidification and anti-seepage wall |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109881660A CN109881660A (en) | 2019-06-14 |
| CN109881660B true CN109881660B (en) | 2021-02-09 |
Family
ID=66929127
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910136348.6A Active CN109881660B (en) | 2019-02-25 | 2019-02-25 | A construction method for scour protection of marine building foundations combined with microbial solidification and anti-seepage wall |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109881660B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111236281A (en) * | 2020-02-24 | 2020-06-05 | 广州万构建筑工程设计有限公司 | Water stopping method for steel sheet pile cofferdam |
| CN111995339A (en) * | 2020-07-16 | 2020-11-27 | 天津大学前沿技术研究院有限公司 | Anti-scouring solidified soil for ocean platform and preparation method thereof |
| CN111926805A (en) * | 2020-09-03 | 2020-11-13 | 华电重工股份有限公司 | Pile foundation protection structure and protection method |
| CN111926806A (en) * | 2020-09-03 | 2020-11-13 | 华电重工股份有限公司 | Pile foundation protection structure and protection method |
| CN112323805B (en) * | 2020-09-15 | 2022-01-25 | 江苏在铭建设工程有限公司 | Fixed catheter traction sensor and method of use |
| CN112663616B (en) * | 2020-11-09 | 2022-04-22 | 中国海洋大学 | Cylindrical grouting equipment and construction method thereof |
| CN115262527B (en) * | 2022-06-07 | 2023-12-22 | 福建永强岩土股份有限公司 | Microorganism grouting device and method applied to marine foundation reinforcement |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2601697B2 (en) * | 1988-08-30 | 1997-04-16 | 清水建設株式会社 | Ground improvement method using microorganisms |
| CN103266592B (en) * | 2013-05-27 | 2015-08-19 | 东南大学 | A kind of method utilizing phosphate mineralized bacterium consolidation loosen loose sand particle |
| CN105386433B (en) * | 2015-12-08 | 2017-06-16 | 南京林业大学 | A kind of microorganism soil-fixing CFG pile composite foundations and construction method |
| CN108008110A (en) * | 2017-10-26 | 2018-05-08 | 重庆大学 | A kind of microorganism based on temperature conditionss cures sand optimization method |
| CN108823259A (en) * | 2018-07-04 | 2018-11-16 | 内蒙古工业大学 | The calcareous glue of microorganism and preparation method, application, sand column and preparation method |
-
2019
- 2019-02-25 CN CN201910136348.6A patent/CN109881660B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109881660A (en) | 2019-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109881660B (en) | A construction method for scour protection of marine building foundations combined with microbial solidification and anti-seepage wall | |
| CN109838113B (en) | A method for sealing cracks in basement roof and exterior wall using microbial grouting | |
| CN111119940B (en) | Grouting construction treatment method | |
| CN106759297A (en) | A kind of construction method of support pile and three pipe high-pressure rotary jet grouting pile deep basal pits | |
| CN108589798A (en) | A kind of large diameter pile foundation wash preventing method and device based on MICP technologies | |
| CN102757104B (en) | A technology for in-situ repair system construction in medium-coarse sand formation | |
| CN209636826U (en) | Water-stop structure of foundation pit in water-rich sand and gravel stratum | |
| CN106884424A (en) | A kind of device and construction method that microorganism solidification is carried out in thin silt | |
| CN109184255A (en) | A method of utilizing microorganism grout sealing outer wall of basement crack | |
| CN113882407A (en) | Landslide control method based on microbial mineralization | |
| CN105464074A (en) | Manual hole digging pile high polymer grouting protection structure and construction method thereof | |
| CN106978795A (en) | A kind of Novel geogrid and its application for the old and new's dyke joint portion | |
| CN112081125B (en) | Bottom sealing structure and construction technology of foundation pit in submerged sand and gravel stratum | |
| CN207193946U (en) | Utilize the device of microorganism induction generation calcium carbonate soil mass consolidation | |
| CN108060678A (en) | A kind of coral Flooding in Borehole bucket base bracing means and installation method based on MICP | |
| CN110241837A (en) | A kind of construction method for preventing basement bottom board from cracking under high artesian geological conditions | |
| CN207862925U (en) | A kind of slip casting casing device | |
| CN204254073U (en) | A kind of pre-stress steel cylinder RPC tubing | |
| CN104164895A (en) | Basement generating no water buoyant force | |
| CN100386483C (en) | High-performance cement-soil continuous wall construction method | |
| CN111648297A (en) | River course in-situ solidification construction method | |
| CN210562188U (en) | Major diameter pile foundation scour prevention grouting device that active and passive protection combined together | |
| CN208486245U (en) | Groundwater reservoir gate shaft based on rubber bag tank sealing | |
| CN203475486U (en) | Basement producing no water buoyancy | |
| CN111535306B (en) | Microbial curing method and irrigation and drainage device suitable for marine soft soil foundation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |