CN111074920A - Construction method for inserting anti-seepage blanket into cement-soil continuous wall to form composite curtain and composite curtain prepared by construction method - Google Patents
Construction method for inserting anti-seepage blanket into cement-soil continuous wall to form composite curtain and composite curtain prepared by construction method Download PDFInfo
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- CN111074920A CN111074920A CN202010047273.7A CN202010047273A CN111074920A CN 111074920 A CN111074920 A CN 111074920A CN 202010047273 A CN202010047273 A CN 202010047273A CN 111074920 A CN111074920 A CN 111074920A
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D19/00—Keeping dry foundation sites or other areas in the ground
- E02D19/06—Restraining of underground water
- E02D19/12—Restraining of underground water by damming or interrupting the passage of underground water
- E02D19/18—Restraining of underground water by damming or interrupting the passage of underground water by making use of sealing aprons, e.g. diaphragms made from bituminous or clay material
Abstract
The invention relates to the technical field of foundation pit waterproof curtains, and discloses a construction method for inserting an anti-seepage blanket into a cement-soil continuous wall to form a composite curtain and the composite curtain prepared by the construction method. The construction method comprises the following specific steps: the construction method can greatly reduce the thickness of the cement continuous wall, can greatly save the construction cost and reduce the construction cost, has small influence on the stratum and the surrounding environment in the construction process, and is particularly suitable for the engineering with strict seepage-proofing effect and needing to penetrate through a sand layer to form the cement continuous wall curtain when the foundation pit supporting structure generates larger deformation.
Description
Technical Field
The invention relates to the technical field of foundation pit waterproof curtains, in particular to a construction method for inserting an anti-seepage blanket into a cement-soil continuous wall to form a composite curtain and the composite curtain prepared by the construction method.
Background
The waterproof curtain is mainly used for preventing or reducing continuous water stopping bodies which are adopted when underground water on the side wall of the foundation pit and the bottom of the foundation pit flows into the foundation pit. In the prior art, the waterproof curtain generally adopts cement soil mixing pile curtain, high-pressure rotary spraying or swinging slurry spraying curtain, mixing-spraying slurry spraying curtain, canal type cement soil wall cutting and other technologies. The waterproof curtain in the form has the following defects: (1) in order to ensure the water-stopping effect, the curtain has a certain thickness, so when the single row of meshed curtain piles are adopted, the pile diameter is generally not less than 800mm, and when the double row of meshed curtain piles are adopted, the pile diameter is not less than 450 mm. The inter-pile meshing width of the single-row meshed curtain piles and the inter-pile and inter-row meshing width of the double-row meshed curtain piles are generally not less than 150mm, and the meshing width can reach 350mm when the water level is higher and the seepage prevention requirement is stricter. The number of cement-soil piles at the occlusion part is large, which causes a great deal of waste. (2) When the curtain piles with larger diameter or more quantity are constructed, the ground layer is greatly disturbed, and then ground settlement is generated, and the surrounding environment is affected. (3) When the foundation pit supporting structure generates large deformation, the through type crack is easily generated on the curtain, the water stopping effect is influenced, and hidden danger is caused to the foundation pit engineering safety. (4) When the curtain pile is constructed in the sand layer, the anti-seepage effect is not easy to guarantee.
Disclosure of Invention
The invention aims to provide a construction method for inserting an impermeable blanket into a cement-soil continuous wall to form a composite curtain and the composite curtain prepared by the construction method.
In order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows:
the invention firstly provides a construction method for inserting an impermeable blanket into a cement-soil continuous wall to form a composite curtain, which comprises the following steps:
(1) constructing the cement-soil continuous wall according to a conventional method;
(2) before the cement-soil continuous wall is initially set, the impermeable blankets are inserted into the cement-soil continuous wall from the top of the cement-soil continuous wall along the depth direction of the cement-soil continuous wall, two adjacent impermeable blankets are in lap joint, and then impermeable materials are injected into lap joint positions of the two adjacent impermeable blankets.
According to the construction method, preferably, the insertion depth of the anti-seepage blanket is less than or equal to the depth of the cement continuous wall, the lap joint width d between two adjacent anti-seepage blankets is 0.02 h-0.05 h, and h represents the insertion depth of the anti-seepage blanket.
According to the construction method described above, preferably, the insertion position of the impermeable blanket is located at the wall thickness center line of the cemented soil continuous wall (i.e., at the thickness center line).
According to the construction method, the cement continuous wall in the step (1) is preferably any one of an engaged cement mixing pile, an engaged high-pressure rotary jet pile, an engaged swinging jet pile and a canal-type cut cement continuous wall.
According to the construction method, preferably, the engaged cement soil mixing pile, the engaged high-pressure jet grouting pile and the engaged pendulum spraying pile are all single-row engaged piles, the pile diameter of the engaged cement soil mixing pile, the engaged high-pressure jet grouting pile and the engaged pendulum spraying pile is 450-650 mm, and the inter-pile engagement width is 150-250 mm; the specific values of the diameter of the piles and the meshing width among the piles are determined according to the specific anti-seepage requirement.
According to the construction method, the thickness of the trench type cutting cement continuous wall is preferably 550 mm-700 mm.
According to the construction method, preferably, the step (2) of injecting the impermeable material into the overlapped part of the two adjacent impermeable blankets is carried out by the following specific operations: and inserting grouting pipes into the lap joint parts of the two adjacent anti-seepage blankets, wherein the bottoms of the grouting pipes are flush with the bottom of the cement-soil continuous wall, and injecting anti-seepage materials into the grouting pipes while lifting the grouting pipes.
According to the construction method, the barrier material in the step (2) is preferably a high polymer barrier material.
According to the construction method, the high polymer impermeable material is preferably a polyurethane grouting material.
According to the construction method, preferably, the insertion depth h of the impermeable blanket is 10 m-50 m; more preferably, the impermeable blanket insertion perpendicularity error is within 1/200.
The invention also provides a composite curtain prepared by the construction method.
According to the composite curtain, the thickness of the composite curtain is 450 mm-700 mm.
Compared with the prior art, the invention has the following positive beneficial effects:
(1) under the condition of achieving the same water-stopping and seepage-proofing effects, the effective thickness of the channel type cut cement-soil continuous wall can be as low as 550mm by adopting the construction method, the mixing piles, the high-pressure rotary spraying piles, the swinging spraying piles and the occlusive cement-soil piles can be arranged in single rows, and the pile diameter can be as low as 450mm, so that compared with the single-row large-diameter occlusive cement-soil pile curtain (the pile diameter is more than or equal to 800 mm), a plurality of rows of occlusive cement-soil pile curtains (the pile diameter is more than or equal to 450 mm) and the channel type cut cement-soil wall (the thickness is more than or equal to 850 mm) in the conventional ultra-deep foundation pit, the construction cost can be greatly saved, and the construction cost can be reduced.
(2) The composite curtain prepared by the construction method of the invention adopts the pile types with smaller diameters for the mixing pile, the high-pressure rotary jet grouting pile, the swinging jet grouting pile and the occluded cement soil pile, so that the disturbance to the stratum in the curtain pile construction process is smaller, the ground settlement is not easy to generate in the construction process, and the influence to the surrounding environment is small; moreover, the anti-seepage blanket does not generate vibration in the inserting process, and has no influence on the surrounding environment.
(3) The seepage-proofing blanket is a flexible structure, and when the foundation pit supporting structure generates large deformation, the water-stopping effect of the seepage-proofing blanket is basically not influenced. Under the condition of achieving the same anti-seepage effect, due to the anti-seepage blanket, the requirements on the anti-seepage and anti-deformation capabilities of the cement-soil continuous wall are reduced, and the anti-deformation and anti-seepage capabilities of the cement-soil are related to the strength of the cement-soil continuous wall, so that the strength requirements of the cement-soil continuous wall can be properly reduced, the construction cost is further reduced, and the construction cost is saved.
(4) According to the invention, the lapping width d between two adjacent anti-seepage blankets is not less than 0.02h and not more than 0.05h (h represents the insertion depth of the anti-seepage blanket), and the arrangement can ensure that the lapping width of the two anti-seepage blankets can still meet the anti-seepage requirement when the anti-seepage blanket is inserted with an error (the error is not more than 1/200) within an allowable range.
(5) When the conventional occlusion type cement-soil continuous wall is adopted, the construction quality is greatly influenced by the stratum; such as: the defects of pile bodies caused by nonuniform stirring of stirring piles in cohesive soil are easy to occur, so that the seepage prevention of the cement continuous wall cannot meet the design requirements; insufficient stirring diameter is easy to occur in the sand layer, so that the occlusion width is not satisfied, and the seepage prevention of the cement continuous wall cannot meet the design requirement. According to the invention, the anti-seepage blanket is inserted into the conventional occlusion type cement continuous wall, and the anti-seepage requirement of the occlusion type cement continuous wall can be still met under the most unfavorable defect condition by utilizing the excellent anti-seepage performance of the anti-seepage blanket.
(6) When the curtain form is adopted, the seepage-proofing blanket can be inserted into the canal type cut cement soil continuous wall with the minimum thickness (limited by construction machinery, the minimum thickness of the canal type cut cement soil continuous wall is 550mm, and when the machinery is updated, the minimum thickness of the invention can be reduced along with the minimum thickness), so that the seepage-proofing requirement is met, and meanwhile, the construction cost is greatly reduced.
(7) The composite curtain prepared by the construction method has the advantages of thin thickness, good seepage-proofing effect and high reliability, and is particularly suitable for projects with strict seepage-proofing effect and needing to penetrate through a sand layer to form the cement-soil continuous wall curtain.
Drawings
FIG. 1 is a schematic view showing a structure of a composite curtain prepared in example 1 of the present invention;
FIG. 2 is a schematic view showing a structure of a composite curtain prepared in example 2 of the present invention;
wherein, 1 is a cement soil mixing pile, 2 is an anti-seepage blanket, 3 is an anti-seepage material, and 4 is a canal type cutting cement soil continuous wall.
Detailed Description
The present invention will be described in further detail with reference to specific examples, but the scope of the present invention is not limited thereto.
Example 1:
a construction method for inserting an impermeable blanket into a cement-soil continuous wall to form a composite curtain comprises the following steps:
(1) constructing a cement soil mixing pile according to a conventional method, wherein the diameter of the pile is 500mm, the meshing width among the piles is 150mm, and the depth is 20 m;
(2) before the initial setting of the constructed cement-soil mixing pile, inserting a first anti-seepage blanket into the constructed cement-soil mixing pile from the thickness center line of the top of the cement-soil mixing pile along the depth direction of the cement-soil mixing pile, wherein the insertion depth of the anti-seepage blanket is equal to the depth of the cement-soil mixing pile (namely the length of the anti-seepage blanket along the depth direction of the cement-soil mixing pile is the same as the depth of the cement-soil mixing pile);
(3) inserting the anti-seepage blanket, continuing to construct the cement-soil mixing pile, inserting a second anti-seepage blanket (the second anti-seepage blanket is inserted in the same way as the first anti-seepage blanket) when the width of the newly constructed cement-soil mixing pile meets the insertion condition, wherein the lap joint width between the second anti-seepage blanket and the first anti-seepage blanket is 500 mm;
(4) after the second anti-seepage blanket is inserted, inserting a grouting pipe at the lap joint part of the first anti-seepage blanket and the second anti-seepage blanket, wherein the bottom of the grouting pipe is flush with the bottom of the cement-soil mixing pile, the grouting pipe is provided with a grouting hole, and anti-seepage materials are injected into the grouting pipe while the grouting pipe is lifted, so that the two adjacent anti-seepage blankets form a whole; wherein the seepage-proofing material is a polyurethane grouting material;
(5) and (5) repeating the steps (1) to (4) until the construction of the whole cement-soil continuous wall is completed.
A composite curtain prepared by the above method has a thickness of 500mm, and a structural view of the composite curtain is shown in FIG. 1.
Example 2:
a construction method for inserting an impermeable blanket into a cement-soil continuous wall to form a composite curtain comprises the following steps:
(1) constructing a channel type cutting cement continuous wall by adopting a TRD (Trench type cutting cement continuous wall construction method), wherein the thickness of the channel type cutting cement continuous wall is 550mm, and the depth is 25 m;
(2) when the width of the constructed canal type cut cement soil continuous wall meets the requirement of inserting an anti-seepage blanket, inserting a first anti-seepage blanket into the constructed canal type cut cement soil continuous wall from the thickness center line of the top of the canal type cut cement soil continuous wall along the depth direction of the canal type cut cement soil continuous wall, wherein the insertion depth of the anti-seepage blanket is equal to the depth of the canal type cut cement soil continuous wall (namely the length of the anti-seepage blanket along the depth direction of the canal type cut cement soil continuous wall is the same as the depth of the canal type cut cement soil continuous wall);
(3) inserting an anti-seepage blanket and simultaneously continuing to construct the canal type cut cement soil continuous wall, when the width of the newly constructed canal type cut cement soil continuous wall meets the requirement of inserting the anti-seepage blanket, inserting a second anti-seepage blanket (the insertion mode of the second anti-seepage blanket is the same as that of the first anti-seepage blanket), wherein the lap joint width between the second anti-seepage blanket and the first anti-seepage blanket is 500 mm;
(4) after the second anti-seepage blanket is inserted, inserting a grouting pipe at the lap joint part of the first anti-seepage blanket and the second anti-seepage blanket, wherein the bottom of the grouting pipe is flush with the bottom of the canal type cut cement continuous wall, the grouting pipe is provided with a grouting hole, and anti-seepage materials are injected into the grouting pipe while the grouting pipe is lifted, so that the two adjacent anti-seepage blankets form a whole; wherein the seepage-proofing material is a polyurethane grouting material;
(5) and (4) repeating the steps (1) to (4) until the construction of the whole ditch type cutting cement-soil continuous wall is completed.
A composite curtain prepared by the above method has a thickness of 550mm, and a structural schematic view of the composite curtain is shown in FIG. 2.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the present invention, but rather as the following description is intended to cover all modifications, equivalents and improvements falling within the spirit and scope of the present invention.
Claims (10)
1. A construction method for inserting an impermeable blanket into a cement-soil continuous wall to form a composite curtain is characterized by comprising the following steps:
(1) constructing the cement-soil continuous wall according to a conventional method;
(2) before the cement-soil continuous wall is initially set, the impermeable blankets are inserted into the cement-soil continuous wall from the top of the cement-soil continuous wall along the depth direction of the cement-soil continuous wall, two adjacent impermeable blankets are in lap joint, and then impermeable materials are injected into lap joint positions of the two adjacent impermeable blankets.
2. The construction method according to claim 1, wherein the insertion depth of the impermeable blanket is less than or equal to the depth of the cement-soil continuous wall, the lap joint width d between two adjacent impermeable blankets is 0.02h ≤ d ≤ 0.05h, and h represents the insertion depth of the impermeable blanket.
3. The construction method according to claim 2, wherein the insertion position of the impermeable blanket is located at a wall thickness centerline of the cement continuous wall.
4. The construction method according to claim 1, wherein the cement continuous wall in the step (1) is any one of a meshing type cement mixing pile, a meshing type high-pressure jet grouting pile, a meshing type swing grouting pile and a channel type cutting cement continuous wall.
5. The construction method according to claim 4, wherein the engaged cement-soil mixing pile, the engaged high-pressure jet grouting pile and the engaged pendulum spraying pile are all single-row engaged piles, the pile diameters of the engaged cement-soil mixing pile, the engaged high-pressure jet grouting pile and the engaged pendulum spraying pile are 450mm to 650mm, and the inter-pile engagement width is 150mm to 250 mm; the thickness of the canal type cutting cement soil continuous wall is 550 mm-700 mm.
6. The construction method according to claim 1, wherein the step (2) of injecting the impermeable material into the overlapped part of the two adjacent impermeable blankets is carried out by: and inserting grouting pipes into the lap joint parts of the two adjacent anti-seepage blankets, wherein the bottoms of the grouting pipes are flush with the bottom of the cement-soil continuous wall, and injecting anti-seepage materials into the grouting pipes while lifting the grouting pipes.
7. The method of claim 6, wherein the barrier material of step (2) is a polymeric barrier material.
8. The construction method according to claim 7, wherein the high polymer barrier material is a polyurethane grouting material.
9. A composite curtain prepared by the construction method of any one of claims 1 to 8.
10. The composite curtain of claim 9, wherein a thickness of the composite curtain is 450mm to 700 mm.
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| CN202010047273.7A CN111074920A (en) | 2020-01-16 | 2020-01-16 | Construction method for inserting anti-seepage blanket into cement-soil continuous wall to form composite curtain and composite curtain prepared by construction method |
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| CN202010047273.7A CN111074920A (en) | 2020-01-16 | 2020-01-16 | Construction method for inserting anti-seepage blanket into cement-soil continuous wall to form composite curtain and composite curtain prepared by construction method |
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| CN112554166A (en) * | 2020-12-03 | 2021-03-26 | 天津大学 | Deep-layer stirring composite wall based on HDPE (high-density polyethylene) membrane and construction method |
| CN113914375A (en) * | 2021-11-24 | 2022-01-11 | 江苏鼎达建筑新技术有限公司 | Composite impervious wall based on geomembrane and cement soil and construction method |
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Application publication date: 20200428 |