阅读说明：本技术 一种管幕与微生物土联合支护结构及其施工方法 (Pipe curtain and microbial soil combined supporting structure and construction method thereof ) 是由 胡俊 杨雨霏 曾东灵 王志鑫 曾晖 佳琳 王伟 李亮 于 2021-07-22 设计创作，主要内容包括：本发明涉及管幕与微生物土联合支护技术领域,尤其涉及一种管幕与微生物土联合支护结构,包括管幕钢管、水平微生物土桩和开挖洞门,所述管幕钢管与水平微生物土桩交替布置在开挖洞门的四周,且相邻两个管幕钢管之间设置有一个或多个水平微生物土桩,若干个管幕钢管与若干个水平微生物土桩一起组合形成大刚度的共同支护受力体系,本发明是将管幕钢管支护形式与水平微生物土桩支护形式进行组合,形成大刚度水密性管幕与微生物土联合支护结构,可以有效控制地下水的流失,保证施工及运营安全,特别适合作为饱和富水软土地层的浅埋大断面地下结构下穿敏感建筑施工时的支护结构。(The invention relates to the technical field of pipe curtain and microbial soil combined support, in particular to a pipe curtain and microbial soil combined support structure which comprises pipe curtain steel pipes, horizontal microbial soil piles and an excavation portal, wherein the pipe curtain steel pipes and the horizontal microbial soil piles are alternately arranged around the excavation portal, and one or more horizontal microbial soil piles are arranged between two adjacent pipe curtain steel pipes, and a plurality of pipe curtain steel pipes and a plurality of horizontal microbial soil piles are combined together to form a common supporting and stress system with large rigidity. The support structure is particularly suitable for the construction of sensitive buildings under shallow-buried large-section underground structures in saturated water-rich soft soil stratums.)

1. The utility model provides a pipe curtain and little biological soil combined supporting structure, includes pipe curtain steel pipe (1), horizontal little biological soil pile (2) and excavation portal (3), its characterized in that: pipe curtain steel pipe (1) and horizontal microorganism soil pile (2) are arranged around excavation portal (3) in turn, and are provided with one or more horizontal microorganism soil pile (2) between two adjacent pipe curtain steel pipes, and a plurality of pipe curtain steel pipe (1) and a plurality of horizontal microorganism soil pile (2) make up together and form the common supporting stress system of big rigidity.

2. The pipe curtain and microorganism soil combined supporting structure is characterized in that concrete is not filled in the pipe curtain steel pipe (1).

3. The pipe curtain and microorganism soil combined supporting structure is characterized in that concrete is filled in the pipe curtain steel pipe (1) at intervals.

4. The pipe curtain and microorganism soil combined supporting structure as claimed in claim 1, wherein the pipe curtain steel pipes (1) are filled with concrete.

5. The pipe curtain and microorganism soil combined supporting structure is characterized in that the shape of the pipe curtain steel pipe (1) and horizontal microorganism soil pile (2) combined supporting structure can be arranged to be circular, rectangular or any other shape.

6. A construction method of a pipe curtain and microbial soil combined supporting structure is characterized by comprising the following steps:

s1, constructing a pipe curtain steel pipe construction working well and a receiving well;

s2, constructing pipe curtain steel pipes, wherein the diameter of each pipe curtain steel pipe is 0.3-2m, and the pipe curtain steel pipes are laid by adopting a pipe jacking method;

s3, filling concrete in the pipe curtain steel pipe, filling the concrete by adopting micro-expansion concrete, and filling the pipe curtain steel pipe with the concrete at intervals, wherein the concrete is completely filled or not filled;

s4, constructing a horizontal microbial soil pile, namely drilling holes between every two pipe curtain steel pipes by using a drilling machine, and inputting prepared slurry into the holes in a high-pressure slurry spraying mode;

s5, excavating in the supporting structure, manufacturing an inner support, then constructing an internal structure section by section, and dismantling the inner support;

and S6, finally forming a complete pipe curtain and microbial soil combined supporting structure.

7. The construction method of a pipe curtain and microbial soil combined supporting structure as claimed in claim 6, wherein in the step S3, after the concrete is filled, bentonite thixotropic slurry is injected into an annular space between the pipe curtain steel pipe and the surrounding soil layer to reduce the frictional resistance between the jacking pipeline and the ground layer.

8. The construction method of a pipe curtain and microbial soil combined supporting structure as claimed in claim 7, wherein in S4, the bacterial liquid is prepared from OD₆₀₀The bacillus pasteurii S.pasteurii and the nutrient salt solution necessary for the vital movement are composed of 1.5, each 1L of the nutrient salt solution contains 6.0g of soybean peptone, 16.0g of tryptone, 5.0g of sodium chloride and 20g of urea, the pH value of the nutrient salt solution is 7.25, and the cementing solution is formed by mixing 0.60-1.50 mol/L calcium chloride solution and 0.60-1.50 mol/L urea solution.

9. The method for constructing a pipe roof and microbial soil combined supporting structure as claimed in claim 7, wherein in the step S4, the high pressure guniting is performed by opening the grout passage, gradually increasing the grout pressure to a pressure of 10MPa or more, and rotating the nozzle at the front of the drill bit by 90 degrees by the grout pressure to protrude and erect from the drill bit. Checking whether the pump pressure reading meets the design requirement (35-40MPa), staying for a certain time when high-pressure guniting is carried out on the hole bottom, then slowly pulling out the drill rod, dragging back the drill rod of 0.3m when the drill rod is pulled out by 0.6m, and carrying out high-pressure rotary spraying at the same time.

Technical Field

The invention relates to the technical field of pipe curtain and microbial soil combined support, in particular to a pipe curtain and microbial soil combined support structure and a construction method thereof.

Background

With the acceleration of the urbanization process of China, large underground structures are built more and more under urban roads or important buildings. For the urban tunnel with shallow-buried large section and short distance, the shield method is uneconomical to construct, and the open excavation method has great interference to the production and life of the city. When the geological conditions are poor, the embedding depth is shallow, and sensitive buildings are arranged at the upper part, the ground settlement is difficult to control if the shallow-buried underground excavation method is adopted for construction, and once construction accidents occur, remarkable social influence is caused. Therefore, how to find a construction method suitable for a shallow-buried large-section underground structure of a saturated water-rich soft soil stratum to penetrate sensitive buildings is very important.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides a pipe curtain and microbial soil combined supporting structure and a construction method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

the pipe curtain and microorganism soil combined supporting structure comprises pipe curtain steel pipes, horizontal microorganism soil piles and an excavation portal, wherein the pipe curtain steel pipes and the horizontal microorganism soil piles are alternately arranged around the excavation portal, one or more horizontal microorganism soil piles are arranged between every two adjacent pipe curtain steel pipes, and the plurality of pipe curtain steel pipes and the plurality of horizontal microorganism soil piles are combined together to form a high-rigidity common supporting stress system.

Preferably, no concrete is filled in the tube curtain steel tube.

Preferably, the pipe curtain steel pipe is filled with concrete at intervals.

Preferably, the pipe curtain steel pipe is filled with concrete.

Preferably, the shape of the pipe curtain steel pipe and horizontal microorganism soil pile combined supporting structure can be arranged to be circular, rectangular or any other shape.

A construction method of a pipe curtain and microbial soil combined supporting structure comprises the following steps:

s1, constructing a pipe curtain steel pipe construction working well and a receiving well;

s2, constructing pipe curtain steel pipes, wherein the diameter of each pipe curtain steel pipe is 0.3-2m, and the pipe curtain steel pipes are laid by adopting a pipe jacking method;

s3, filling concrete in the pipe curtain steel pipe, filling the concrete by adopting micro-expansion concrete, and filling the pipe curtain steel pipe with the concrete at intervals, wherein the concrete is completely filled or not filled;

s4, constructing a horizontal microbial soil pile, namely drilling holes between every two pipe curtain steel pipes by using a drilling machine, and inputting prepared slurry into the holes in a high-pressure slurry spraying mode;

s5, excavating in the supporting structure, manufacturing an inner support, then constructing an internal structure section by section, and dismantling the inner support;

and S6, finally forming a complete pipe curtain and microbial soil combined supporting structure.

Preferably, in S3, after filling the concrete, thixotropic bentonite slurry is injected into the annular space between the pipe curtain steel pipe and the surrounding soil layer to reduce the frictional resistance between the jacking pipe and the ground layer.

Preferably, in S4, the bacterial solution is composed of bacillus pasteurii s.pasteurii with OD600 ═ 1.5 and nutrient salt solution necessary for its life activity, each 1L of nutrient salt solution contains 6.0g of soybean peptone, 16.0g of tryptone, 5.0g of sodium chloride and 20g of urea, the pH of the nutrient salt solution is 7.25, and the cementing solution is formed by mixing calcium chloride solution with concentration of 0.60mol/L to 1.50mol/L and urea solution with concentration of 0.60mol/L to 1.50 mol/L.

Preferably, in S4, the high-pressure shotcrete is erected by opening the slurry passage, gradually raising the slurry pressure to a pressure of 10MPa or more, and rotating the front nozzle of the drill by 90 degrees by the slurry pressure. Checking whether the pump pressure reading meets the design requirement (35-40MPa), staying for a certain time when high-pressure guniting is carried out on the hole bottom, then slowly pulling out the drill rod, dragging back the drill rod of 0.3m when the drill rod is pulled out by 0.6m, and carrying out high-pressure rotary spraying at the same time.

The invention has the beneficial effects that:

1. the invention combines the pipe curtain steel pipe support form with the horizontal microorganism soil pile support form to form the large-rigidity water-tightness pipe curtain and microorganism soil combined support structure, can effectively control the loss of underground water, ensures the safety of construction and operation, and is particularly suitable for being used as the support structure when a shallow-buried large-section underground structure of a saturated water-rich soft soil stratum passes through sensitive buildings.

2. Compared with the existing pipe curtain method, the number of the pipe curtain steel pipes can be greatly reduced, the reduced pipe curtain steel pipe supporting function is replaced by the horizontal microorganism soil piles, and the construction period and the cost can be saved; compared with a single horizontal microbial soil pile supporting form, the rigidity of the supporting structure is greatly improved, the deformation of the earth surface can be effectively controlled, and the safety is good. The invention is particularly suitable for being used as a supporting structure of a shallow-buried large-section underground structure of a saturated water-rich soft soil stratum during sensitive building construction.

Drawings

FIG. 1 is a flow chart of the construction process for constructing underground engineering by using a pipe curtain and microbial soil combined supporting structure provided by the invention;

FIG. 2 is a first combined supporting structure of a pipe curtain and microbial soil, wherein a pipe curtain steel pipe is not filled with concrete;

FIG. 3 is a second combined supporting structure of a pipe curtain and microbial soil, which is provided by the invention, wherein concrete is filled in pipe curtain steel pipes at intervals;

fig. 4 shows a third combined supporting structure of a pipe curtain and microbial soil, which is provided by the invention, wherein the pipe curtain steel pipe is completely filled with concrete.

In the figure: 1 pipe curtain steel pipe, 2 horizontal microorganism soil piles, 3 excavation portal, 4 pipe curtain steel pipes after filling the concrete.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In the first embodiment, referring to fig. 2, a pipe curtain and microbial soil combined supporting structure includes pipe curtain steel pipes 1, horizontal microbial soil piles 2 and an excavation portal 3, the pipe curtain steel pipes 1 and the horizontal microbial soil piles 2 are alternately arranged around the excavation portal 3, one or more horizontal microbial soil piles 2 are arranged between two adjacent pipe curtain steel pipes, no concrete is filled in each pipe curtain steel pipe 1, and the pipe curtain steel pipes 1 and the horizontal microbial soil piles 2 are combined together to form a large-rigidity common supporting stress system, and the shape of the pipe curtain steel pipe 1 and the horizontal microbial soil pile 2 combined supporting structure can be arranged to be circular, rectangular or any other shape.

In a second embodiment, referring to fig. 3, a pipe curtain and microbial soil combined supporting structure includes pipe curtain steel pipes 1, horizontal microbial soil piles 2 and an excavation portal 3, the pipe curtain steel pipes 1 and the horizontal microbial soil piles 2 are alternately arranged around the excavation portal 3, one or more horizontal microbial soil piles 2 are arranged between two adjacent pipe curtain steel pipes, concrete is filled in the pipe curtain steel pipes 1 at intervals, and the pipe curtain steel pipes 1 and the horizontal microbial soil piles 2 are combined together to form a combined supporting structure of the pipe curtain steel pipes 1 and the horizontal microbial soil piles 2 of a high-rigidity common supporting stress system, and the combined supporting structure can be arranged in a circular shape, a rectangular shape or any other shape.

In the third embodiment, referring to fig. 4, a pipe curtain and microbial soil combined supporting structure includes pipe curtain steel pipes 1, horizontal microbial soil piles 2 and an excavation portal 3, the pipe curtain steel pipes 1 and the horizontal microbial soil piles 2 are alternately arranged around the excavation portal 3, one or more horizontal microbial soil piles 2 are arranged between two adjacent pipe curtain steel pipes, concrete is filled in each pipe curtain steel pipe 1, the pipe curtain steel pipes 1 and the horizontal microbial soil piles 2 are combined together to form a high-rigidity common supporting stress system, and the pipe curtain steel pipes 1 and the horizontal microbial soil piles 2 combined supporting structure can be arranged in a circular shape, a rectangular shape or any other shape.

A construction method of a pipe curtain and microbial soil combined supporting structure comprises the following steps:

s1, constructing a pipe curtain steel pipe construction working well and a receiving well;

s2, constructing pipe curtain steel pipes, wherein the diameter of each pipe curtain steel pipe is 0.3-2m, and the pipe curtain steel pipes are laid by adopting a pipe jacking method;

s3, filling concrete in the pipe curtain steel pipe, filling the concrete with micro-expansion concrete, filling the pipe curtain steel pipe with the concrete at intervals, filling the concrete completely or not, and injecting bentonite thixotropic slurry into an annular space between the pipe curtain steel pipe and a surrounding soil layer after filling the concrete to reduce the frictional resistance between a jacking pipeline and the stratum;

s4, constructing a horizontal microbial soil pile, drilling holes between every two pipe-curtain steel pipes by a drilling machine, the prepared slurry is input into a hole in a high-pressure spraying manner, the bacteria liquid is composed of pasteurella S.pasteurii with the concentration OD600 of 1.5 and nutrient salt solution necessary for life activities, each 1L of nutrient salt solution contains 6.0g of soybean peptone, 16.0g of tryptone, 5.0g of sodium chloride and 20g of urea, the pH value of the nutrient salt solution is 7.25, the cementing solution is formed by mixing calcium chloride solution with the concentration of 0.60-1.50 mol/L and urea solution with the concentration of 0.60-1.50 mol/L, the high-pressure spraying slurry is formed by opening a slurry channel, gradually increasing the pressure of the slurry to enable the pressure of the slurry to be more than 10MPa, and enabling a front nozzle of a drill bit to rotate 90 degrees through the pressure of the slurry to extend out of the drill bit and stand upright. Checking whether the pump pressure reading meets the design requirement (35-40MPa), staying for a certain time when high-pressure guniting is carried out on the hole bottom, then slowly pulling out the drill rod, dragging back the drill rod of 0.3m when the drill rod is pulled out by 0.6m, and carrying out high-pressure rotary spraying at the same time;

s5, excavating in the supporting structure, manufacturing an inner support, then constructing an internal structure section by section, and dismantling the inner support;

and S6, finally forming a complete pipe curtain and microbial soil combined supporting structure.

The invention combines the pipe curtain steel pipe support form with the horizontal microorganism soil pile support form to form the large-rigidity water-tightness pipe curtain and microorganism soil combined support structure, can effectively control the loss of underground water, ensures the safety of construction and operation, and is particularly suitable for being used as the support structure when a shallow-buried large-section underground structure of a saturated water-rich soft soil stratum passes through sensitive buildings.

Compared with the existing pipe curtain method, the number of the pipe curtain steel pipes can be greatly reduced, the reduced pipe curtain steel pipe supporting function is replaced by the horizontal microorganism soil piles, and the construction period and the cost can be saved; compared with a single horizontal microbial soil pile supporting form, the rigidity of the supporting structure is greatly improved, the deformation of the earth surface can be effectively controlled, and the safety is good. The invention is particularly suitable for being used as a supporting structure of a shallow-buried large-section underground structure of a saturated water-rich soft soil stratum during sensitive building construction.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.