A rigid cement soil construction system for tunnel excavation construction

Abstract

The present invention relates to the field of underground construction technology, in particular to a rigid cement soil construction system used in tunnel excavation construction, comprising a cement soil primary support structure, construction equipment, a starting well and a receiving well, wherein the starting well and the receiving well are well bodies dug from the ground downward, and the starting well and the receiving well are arranged at intervals to leave a construction space; the construction equipment is arranged at the starting well, and a plurality of cement soil primary support structures are arranged and connected adjacently, and are installed in the construction space below the ground, and each cement soil primary support structure is respectively composed of an I-beam, a corrugated steel plate, a casing and an in-situ cement soil body; the cement soil primary support structure of the present invention uses slag and cement slurry cut by in-situ mixing, and does not need to consume a large amount of steel during the construction process, and the construction process is simple and fast, which can shorten the construction period and reduce the construction cost; and its waterproof and water-stopping effect is greatly improved, and the in-situ mixing structure also greatly reduces the disturbance of the stratum during construction, which is better than the steel pipe curtain construction.

Description

Technical Field

[0001] The invention relates to the technical field of underground construction, in particular to a rigid cement soil construction system used in tunnel excavation construction. Background Art

[0002] With the progress of urbanization, the utilization rate of underground space is constantly improving, and the excavation process of more and more underground projects is accelerating. However, due to the limitations of urban development speed and long-term planning, underground project construction has always encountered various difficulties in the past, especially in: 1. When excavating underground projects, it is necessary to protect cables and important buildings above the excavation surface; 2. During the excavation of underground projects, attention should be paid to waterproofing and anti-seepage measures.

[0003] At present, the pipe curtain method is generally used to solve the above construction difficulties. The pipe curtain method is as follows: between the starting well and the receiving well, the steel pipe is pushed into the soil through the jacking equipment, and each single pipe is connected to the side of the steel pipe by the lock mouth to form a pipe row, and a water-stopping agent is injected into the gap of the lock mouth to meet the water-stopping requirements to form an advanced support. Then, under the protection of the pipe curtain, the underground box culvert structure is constructed. However, this construction method still has many shortcomings that are difficult to overcome: (1) The steel pipe pushed into the soil cannot be recovered, resulting in a waste of resources, large project investment and high cost; (2) When pushing the steel pipe, a large amount of debris and mud needs to be discharged, causing environmental pollution; (3) When pushing the pipe into the shallow overburden layer, a back-soil effect will be generated; (4) The water tightness of the pipe curtain is poor, and the waterproof and water-stopping effect is general; (5) When pushing the steel pipe, the stratum will be disturbed, which may cause uneven settlement and deformation of the ground. Summary of the invention

[0004] To solve the above problems, the present invention aims to disclose a field of underground construction technology, and in particular, a rigid cement soil construction system used in tunnel excavation construction, which provides temporary support and water-stopping effect for underground construction through a rigid cement soil continuous wall, thereby quickly improving construction efficiency.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a rigid cement soil construction system used in tunnel excavation construction, characterized in that the construction system mainly includes a cement soil primary support structure, construction equipment, a starting well and a receiving well, wherein the starting well and the receiving well are well bodies dug from the ground downward, and the starting well and the receiving well are spaced apart to leave construction space; the construction equipment is arranged at the starting well, and the construction equipment includes a pipe jacking machine and a mixing and crushing device; the cement soil primary support structure is provided with a plurality of parallel Adjacent connection, installed in the construction space below the ground, each cement soil primary support structure is composed of an I-beam, a corrugated steel plate, a casing and an in-situ cement soil body, wherein the casing is a circular short tubular structure, the I-beam is formed into an I-shaped steel plate structure and installed in the casing, a pair of corrugated steel plates are installed on the upper and lower surfaces of the I-beam, and two opposite edges of the corrugated steel plates are tightly against the side wall of the casing, the in-situ cement soil body is a block structure filled in the casing and surrounding the I-beam and the corrugated steel plate, and the cement soil primary support structure forms a pile structure as a whole.

[0006] Preferably, each adjacent cement-soil primary support structure is overlapped and connected to form an integral frame-type installation structure.

[0007] A construction method for a rigid cement soil construction system used in tunnel excavation construction is used, characterized in that the construction method mainly comprises the following steps:

[0008] S1. Equipment working well for constructing cement soil primary support structure, including starting well and receiving well;

[0009] S2. Set the positioning auxiliary line of the cement soil primary support structure on the equipment working pit;

[0010] S3, preparing cement soil according to the material mix ratio;

[0011] S4. Adjust the cutting drill bit guidance accuracy during the construction of cement soil primary support structure;

[0012] S5, forming an in-situ cement soil body by mixing and stirring the ingredients, and forming an integral pile structure after molding;

[0013] S6, adjusting the center distance of each cement soil pile structure to form a connected frame installation structure;

[0014] S7. Carry out recycling work after the construction is completed.

[0015] Preferably, the step S1 further includes:

[0016] 1) Plan the construction area and determine the installation area of ​​the cement soil primary support structure;

[0017] 2) Identify the location of the equipment working pit outside the construction area;

[0018] 3) Dig equipment working pits to provide operating space for construction equipment.

[0019] Preferably, it is characterized in that the step S2 also includes:

[0020] 1) Set positioning auxiliary lines on the equipment working well, and use a level ruler to calibrate the mechanical frame before drilling to determine the horizontal positioning of the cement soil primary support structure;

[0021] 2) Control the construction accuracy of the drilling and the horizontal center distance of the cement soil primary support structure pile.

[0022] Preferably, the material composition for preparing cement soil in step S3 is: cement slurry: cut soil: other admixtures.

[0023] Preferably, in step S4, after adjusting the guiding accuracy of the cutting drill bit during the construction of the cement soil primary support structure, the cutting drill bit is used to drill a standard hole first during construction, and then a correctable drill bit with a gyroscope is used to track the forward direction of the cutting drill bit in real time.

[0024] Preferably, the step S5 further includes:

[0025] 1) In the process of the drill bit breaking and cutting the soil, the casing and prefabricated profiles are continuously pulled, and the prefabricated profiles include I-beams and corrugated steel plates;

[0026] 2) Mixing and stirring the crushed cutting soil with cement paste in situ in the casing to initially form in-situ cement soil;

[0027] 3) After solidification, the in-situ cement soil and prefabricated profiles form a cement soil primary support pile structure with a certain strength.

[0028] Preferably, in step S6, steps S4 and S5 are repeated, and the center distance between adjacent cement soil piles is adjusted at the same time to complete the overlap between the piles and form a framework installation structure of the cement soil primary support structure for waterproofing, water stopping and temporary support.

[0029] Preferably, in step S7, after the horizontal cement soil primary support structure is formed, cleaning and recycling work is carried out to recover the construction equipment.

[0030] The beneficial effects of the present invention are as follows: the cement soil primary support structure of the present invention uses the slag and cement slurry that are cut and mixed in situ, so there is no need to discharge a large amount of slag, and compared with the traditional jacking pipe curtain, the pollution is reduced, which is in line with green environmental protection development; and the present invention does not need to consume a large amount of steel during the construction process, the construction process is simple and fast, and the construction period can be shortened and the construction cost can be reduced; at the same time, after adopting the cement soil primary support structure and construction method of the present invention, its waterproof and water-stopping effect is much better than that of the steel pipe curtain, and the in-situ mixed cement soil primary support structure also greatly reduces the disturbance of the stratum during construction, which is better than the steel pipe curtain construction.

[0031] Firstly, the present invention adopts the construction equipment of cement soil primary support structure, which realizes the functions of cutting, stirring, conveying cement slurry and the like on the basis of the functions of jacking, guiding and soil discharge of traditional jacking pipe equipment, and integrates the crushing, cutting, collecting and conveying functions in the jacking power device of the construction equipment, and combines the slurry feeding and stirring systems to realize the formation of cement soil primary support structure; secondly, the present invention is applied to the cement soil primary support structure of underground tunnel excavation, plays the role of optimizing and improving water stopping, waterproofing and temporary support, and also protects the cement soil primary support structure through the construction method; thirdly, since an important function of the cement soil primary support structure of the present invention is waterproofing, for the intersecting parts of the cement soil primary support structure, the horizontal center distance of the pile body in the cement soil primary support structure is strictly controlled in the construction method to control the continuity and waterproofing performance of the overlap between the piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the construction of the cement soil primary support structure of the present invention.

[0033] Figure 2 It is a horizontal cross-sectional view of the cement soil primary support structure pile body of the present invention.

[0034] Figure 3 It is a horizontal cross-sectional view of the cement soil primary support structure pile bodies of the present invention.

[0035] Figure 4 It is a top view schematic diagram of the overall installation of the cement soil primary support structure of the present invention.

[0036] Figure 5 It is a construction process diagram of the cement soil primary support structure of the present invention.

[0037] Notes on the attached figures: 1-cement soil primary support structure, 2-construction equipment, 3-starting well, 4-receiving well, 5-blind excavation construction area, 11-I-beam, 12-corrugated steel plate, 13-casing, 14-in-situ cement soil body, 21-pipe jacking machine, 22-mixing and crushing device. DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings:

[0039] A rigid cement soil construction system for tunnel excavation construction, the construction system mainly comprises a cement soil primary support structure 1, construction equipment 2, a starting well 3 and a receiving well 4, wherein the starting well 3 and the receiving well 4 are well bodies dug from the ground downward, and the starting well 3 and the receiving well 4 are spaced apart to leave construction space; the construction equipment 2 is arranged at the starting well 3, the construction equipment 2 mainly comprises a pipe jacking machine 21, a mixing and crushing device 22, in addition to the jacking, crushing and mixing power, it also involves a power device for guiding, discharging, cutting and pulling profiles, as well as a level, a mechanical frame, a cutting drill bit with grouting function, etc.; the cement soil primary support structure 1 is provided with a plurality of adjacently connected ones, installed in the construction space below the ground, each The cement soil primary support structure 1 is composed of an I-beam 11, a corrugated steel plate 12, a casing 13 and an in-situ cement soil body 14, wherein the casing 13 is a short circular tubular structure, the I-beam 11 is formed into an I-shaped steel plate structure and installed in the casing 13, a pair of corrugated steel plates 12 are installed on the upper and lower surfaces of the I-beam 11, and two opposite edges of the corrugated steel plates 12 are tightly against the side walls of the casing 13, and the in-situ cement soil body 14 is a block structure filled in the casing 13 and surrounding the I-beam 11 and the corrugated steel plate 12, and the cement soil primary support structure 1 forms a pile structure as a whole; each adjacent cement soil primary support structure 1 is overlapped and connected, and is connected to form an integral frame-type installation structure, and the area within the frame is a dark excavation construction area 5;

[0040] A construction method of a rigid cement soil construction system for tunnel excavation construction is used, and the construction method mainly comprises the following steps:

[0041] S1, constructing the equipment working well of the cement soil primary support structure 1, including the starting well 3 and the receiving well 4;

[0042] The step S1 also includes:

[0043] 1) Plan the scope of the construction area and determine the installation area of ​​the cement soil primary support structure 1;

[0044] 2) Identify the location of the equipment working pit outside the construction area;

[0045] 3) Dig an equipment working pit to provide operating space for the construction equipment 2.

[0046] S2. Setting the positioning auxiliary line of the cement soil primary support structure 1 on the equipment working pit;

[0047] The step S2 also includes:

[0048] 1) Set positioning auxiliary lines on the equipment working pit, and use a level ruler to calibrate the mechanical frame before drilling to determine the horizontal positioning of the cement soil primary support structure 1;

[0049] 2) Control the construction accuracy of the drilling holes and the horizontal center distance of the cement soil primary support structure 1 pile body. The center distance of the cement soil primary support structure 1 pile body directly affects the continuity and waterproof performance of the overlap between the piles.

[0050] S3, preparing cement soil according to the material mix ratio;

[0051] The material composition for preparing cement soil in step S3 is: cement paste: cut soil: other admixtures. Since the mechanical indexes of cement soils with different cements, different soils and different mix ratios are quite different, the amount of cement and admixtures added is determined through field soil tests. The injected cement paste is reasonably mixed according to the conditions of the engineering soil, and then the above material mix ratio is determined.

[0052] S4, regulating the cutting drill bit guidance accuracy during the construction of the cement soil primary support structure 1;

[0053] In the step S4, after adjusting the guiding accuracy of the cutting drill bit during the construction of the cement soil primary support structure 1, the cutting drill bit is used to drill a standard hole first during the construction, and then a deviation-correcting drill bit with a gyroscope is used to track the forward direction of the cutting drill bit in real time, so as to directly control the trajectory of the drill bit excavation through the wedge plate at the front end of the drill bit;

[0054] S5, forming an in-situ cement soil body 14 by mixing and stirring the ingredients, and forming an integral pile structure after molding;

[0055] The step S5 further comprises:

[0056] 1) In the process of the drill bit breaking and cutting the soil, the casing 13 and the prefabricated profile are continuously pulled, and the prefabricated profile includes an I-beam 11 and a corrugated steel plate 12;

[0057] 2) Mixing the crushed cutting soil with cement paste in situ in the casing 13 to initially form in-situ cement soil, which has a certain strength;

[0058] 3) After the in-situ cement soil and prefabricated profiles are solidified, a cement soil primary support structure 1 pile structure with a certain strength is formed;

[0059] S6, adjusting the center distance of each cement soil pile structure to form a connected frame installation structure;

[0060] In step S6, step S4 and step S5 are repeated, and the center distance between adjacent cement soil pile bodies is adjusted at the same time, and the overlap work between the pile bodies is completed to form a frame-type installation structure of the cement soil primary support structure 1 for waterproofing, water stopping and temporary support;

[0061] S7. Carry out recycling work after the construction is completed;

[0062] In the step S7, after the horizontal cement soil primary support structure 1 is formed, cleaning and recycling work is carried out to recycle the construction equipment 2 such as the cutting grouting drill bit and the mechanical frame, and the steel casing 13.

[0063] The present invention is based on the innovation of pipe curtain method technology. The soil cut by excavation is fully mixed and stirred with cement slurry according to a proportion, and corrugated steel and I-beam 11 are added to form a rigid cement soil primary support structure 1. It is a construction method that can play a role of waterproofing and water stopping and temporary support for the dark excavation method. Since its cement soil is formed by in-situ mixing of slag and cement slurry, the impact on the surrounding environment and stratum disturbance is extremely small. At the same time, a power front-end device with cutting, crushing, mixing and traction profiles is adopted to achieve in-situ mixing of cement soil in the hole, and by traction of the added profiles, the performance of cement soil is greatly improved, and the strength of the cement soil primary support structure 1 is guaranteed. It is suitable for the underpass of existing subways, the excavation of stations under water-rich geological conditions, the initial support of tunnels in soft and broken strata, etc., solves the problem of waterproofing and water stopping during dark excavation construction, and plays a role of temporary support. It is particularly suitable for dark excavation construction in soft, water-rich, gravel soil strata and composite strata.

[0064] The present invention uses a cutting drill bit with a grouting function to cut the soil and then mix it with cement slurry in the casing 13 to form a continuous in-situ cement soil integral primary support structure, so as to improve the problem of water stopping and water permeability, play a role of temporary support, and is suitable for strata with relatively complex soil, mainly including soft strata, water-rich strata, gravel strata, and soft and hard composite strata. Compared with the traditional steel pipe curtain construction method and the freezing method construction method, it has the advantages of recycling the cut slag, reducing the damage of mud to the environment and the use of steel, and meeting the national green environmental protection requirements; reducing the disturbance of the stratum during construction, reducing the probability of engineering accidents, and can replace the traditional steel pipe curtain and freezing method construction during dark excavation construction; in the present invention, the casing 13 used can be a threaded steel casing 13, which is pushed forward section by section between the two working wells, and the steel casing 13 is reduced to 1.5m, and the top The next section will be locked with the previous section of steel casing 13 by means of the threaded connection of steel casing 13. After the primary support structure is completed, the steel casing 13 will be pulled out from the working well for recovery. The cutter head of the construction equipment 2 will destroy the soil during the excavation process. There is a connecting channel between the cutter head and the steel casing 13. The destroyed soil will be input into the steel casing 13 by means of the connecting channel, and a reasonably proportioned cement slurry will be added at the same time. The soil after cutting and crushing will be mixed and stirred with the reasonably proportioned cement slurry in situ in the casing 13 to initially form an in-situ cement soil with a certain strength.

[0065] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Technical personnel in this industry can make some deformation and modifications under the inspiration of this technical solution. Any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A construction method for a rigid cement soil construction system used in tunnel excavation construction, characterized in that: The construction system mainly includes a cement soil primary support structure, construction equipment, a starting well and a receiving well, wherein the starting well and the receiving well are well bodies dug from the ground downwards, and the starting well and the receiving well are spaced apart to leave a construction space; the construction equipment is arranged at the starting well, and the construction equipment includes a pipe jacking machine and a mixing and crushing device; the cement soil primary support structure is provided with a plurality of adjacently connected structures, and is installed in the construction space below the ground, and each cement soil primary support structure is respectively composed of an I-beam, a corrugated steel plate, a casing and an in-situ cement soil body, wherein the casing is a circular short tubular structure, the I-beam is formed into an I-shaped steel plate structure and is installed in the casing, a pair of corrugated steel plates are installed on the upper and lower surfaces of the I-beam, and two of the opposite edges of the corrugated steel plates are tightly against the side wall of the casing, and the in-situ cement soil body is a block structure filled in the casing and surrounding the I-beam and the corrugated steel plate, and the cement soil primary support structure as a whole forms a pile structure; The construction method mainly comprises the following steps: S1. Equipment working well for constructing cement soil primary support structure, including starting well and receiving well; S2. Set the positioning auxiliary line of the cement soil primary support structure on the equipment working pit; S3, preparing cement soil according to the material mix ratio; S4. Adjust the cutting drill bit guidance accuracy during the construction of cement soil primary support structure; S5, forming an in-situ cement soil body by mixing and stirring the ingredients, and forming an integral pile structure after molding; specifically, it also includes: 1) in the process of crushing and cutting the soil body by the drill bit, continuously pulling the casing and the prefabricated profile, the prefabricated profile includes an I-beam and a corrugated steel plate; 2) mixing and stirring the crushed cut soil body with cement slurry in situ in the casing to initially form an in-situ cement soil; 3) after the in-situ cement soil and the prefabricated profile are solidified, a cement soil primary support structure pile structure with a certain strength is formed; S6, adjusting the center distance of each cement soil pile structure to form a connected frame installation structure; S7. Carry out recycling work after the construction is completed.

2. The construction method of a rigid cement soil construction system for tunnel excavation construction according to claim 1, characterized in that: The adjacent cement-soil primary support structures are overlapped and connected to form an integral frame-type installation structure.

3. The construction method of a rigid cement soil construction system for tunnel excavation construction according to claim 1, characterized in that: The step S1 also includes: 1) Plan the construction area and determine the installation area of ​​the cement soil primary support structure; 2) Identify the location of the equipment working pit outside the construction area; 3) Dig equipment working pits to provide operating space for construction equipment.

4. The construction method of a rigid cement soil construction system for tunnel excavation construction according to claim 1, characterized in that: The step S2 also includes: 1) Set positioning auxiliary lines on the equipment working well, and use a level ruler to calibrate the mechanical frame before drilling to determine the horizontal positioning of the cement soil primary support structure; 2) Control the construction accuracy of the drilling and the horizontal center distance of the cement soil primary support structure pile.

5. The construction method of a rigid cement soil construction system for tunnel excavation construction according to claim 1, characterized in that: The material composition for preparing cement soil in step S3 is: cement paste: cut soil: other admixtures.

6. The construction method of a rigid cement soil construction system for tunnel excavation construction according to claim 1, characterized in that: In step S4, after adjusting the guiding accuracy of the cutting drill bit during the construction of the cement soil primary support structure, the cutting drill bit is used to drill a standard hole first during the construction, and then a deviation-correcting drill bit with a gyroscope is used to track the forward direction of the cutting drill bit in real time.

7. The construction method of a rigid cement soil construction system for tunnel excavation construction according to claim 1, characterized in that: In step S6, steps S4 and S5 are repeated, and the center distance between adjacent cement soil pile bodies is adjusted at the same time to complete the overlap work between the pile bodies, so as to form a framework installation structure of the cement soil primary support structure for waterproofing, water stopping and temporary support.

8. The construction method of a rigid cement soil construction system for tunnel excavation construction according to claim 1, characterized in that: In step S7, after the horizontal cement soil primary support structure is formed, cleaning and recycling work is carried out to recover the construction equipment.

Images