CN117468939A

CN117468939A - Tunnel construction method

Info

Publication number: CN117468939A
Application number: CN202311357366.XA
Authority: CN
Inventors: 邹杨; 朱朋刚; 马军山; 何文建; 刘威杰; 马瑞成; 万珲; 苏志伟; 刘立峰; 文宇
Original assignee: China Railway 20th Bureau Group Corp; Third Engineering Co Ltd of China Railway 20th Bureau Group Co Ltd
Current assignee: China Railway 20th Bureau Group Corp; Third Engineering Co Ltd of China Railway 20th Bureau Group Co Ltd
Priority date: 2023-10-18
Filing date: 2023-10-18
Publication date: 2024-01-30

Abstract

The invention relates to the technical field of tunnel construction, in particular to a tunnel construction method, which comprises the steps of carrying out excavation construction on a first construction section in a preset construction area to form a first tunnel face, carrying out excavation construction on the first construction section which is remained in the first tunnel face to form a second tunnel face when the excavation length of the first tunnel face from a second construction section is a preset distance, carrying out pipe shed construction on the second tunnel face towards the second construction section to form an advanced support body in a geological body, and carrying out pre-splitting crushing excavation construction on the advanced support body by adopting a hydraulic splitting rod according to the extending direction of a tunnel.

Description

Tunnel construction method

Technical Field

The invention relates to the technical field of tunnel construction, in particular to a tunnel construction method.

Background

Tunnels refer to engineering structures buried in the ground and are a form of human use of underground space. The international economic collaboration and development organization in 1970 defined it as "a cavity with a cross-sectional area greater than 2 square meters constructed in any way, in a specified shape and size, under the ground".

Tunnels can be classified into traffic tunnels, hydraulic tunnels, municipal tunnels, mine tunnels, military tunnels, and the like.

Common construction methods for tunnel construction include blasting and shield methods. When constructing mountain tunnels, blasting is generally used, however, when the tunnel passes through an existing building, if the tunnel is excavated by blasting, the safety of the existing building is affected, and if the tunnel is constructed by shield method, the cost is very high.

Disclosure of Invention

The invention mainly aims to provide a tunnel construction method, which aims to solve the technical problems that when a tunnel passes through an existing building in the prior art, if a blasting method is adopted for tunnel excavation construction, the safety of the existing building is influenced, and if a shield method is adopted for construction, the cost is very high.

In order to achieve the above object, in a first aspect, the present invention provides a tunnel construction method, where the tunnel construction method is used for constructing a tunnel entrance section of the tunnel shallow buried under an existing building, and the tunnel entrance section is formed with a first construction section and a second construction section buried under the existing building along a length direction of the tunnel;

the tunnel construction method comprises the following steps:

in a preset construction area, carrying out excavation construction on the first construction section to form a first tunnel face;

when the excavation length of the first tunnel face from the second construction section is a preset distance, performing excavation expansion construction on the rest first construction sections on the first tunnel face to form a second tunnel face; the excavation area of the second tunnel face is larger than that of the first tunnel face;

performing medium pipe shed construction on the second tunnel face towards the second construction section so as to form an advanced support body in the geological body;

and carrying out pre-cracking crushing excavation construction on the advanced support body by adopting a hydraulic splitting rod according to the extending direction of the tunnel.

Optionally, the step of performing excavation construction on the first construction section in a preset construction area according to a preset requirement to form a first tunnel face includes:

carrying out excavation construction on the first construction section in a preset construction area to obtain a section to be supported;

and installing an arch frame in the section to be supported to form the first tunnel face.

Optionally, after the step of installing an arch frame in the section to be supported to form the first face, the method further includes:

hole position lofting is conducted on the first tunnel face, and a plurality of first drilling holes are formed;

and welding hole site locating frames on all the first drilling holes in sequence.

Optionally, after the step of welding the hole site locator on all the first drill holes in sequence, the method further includes:

the pipe shed machine is located on the first tunnel face;

and sequentially drilling all the first drilling holes by using the pipe shed machine to form a first pipe shed.

Optionally, after the step of sequentially drilling the pipe body for all the first holes by using the pipe-shed machine to form a first pipe shed, the method further includes:

and excavating the first face, and acquiring the distance between the first face and the second construction section.

Optionally, after the step of performing excavation construction on the first face and obtaining a distance between the first face and the second construction section, the method further includes:

and continuing to excavate when the distance between the first tunnel face and the second construction section is greater than the preset distance, until the distance between the first tunnel face and the second construction section is the preset construction distance, and executing the step of expanding excavation construction on the first tunnel face and the rest of the first construction section to form the second tunnel face when the excavation length between the first tunnel face and the second construction section is the preset distance.

Optionally, the step of performing a middle pipe shed construction at the second tunnel face towards the second construction section to form a pre-support body in the geological body comprises the following steps:

drilling a plurality of holes in the second construction section of the second working face facing the front of the current working face;

respectively installing the guide pipes with corresponding preset lengths in all the holes;

and grouting all the guide pipes to obtain the pipe shed so as to form an advanced support body in the geological body.

Optionally, the step of installing the pipes with the corresponding preset lengths in all the holes respectively includes:

respectively installing pipe joints with a first length in all the holes;

and lengthening the corresponding pipe joint according to the preset drilling depth to obtain the corresponding guide pipe with the preset length.

Optionally, the step of performing pre-splitting, crushing and excavating construction on the advanced support body by adopting a hydraulic splitting rod according to the extending direction of the tunnel includes:

according to the extending direction of the tunnel, pre-cracking and crushing the advanced support body by adopting a hydraulic splitting rod to form a body to be excavated;

and crushing and excavating the body to be excavated by adopting a crushing head.

Optionally, the geologic body has megaliths formed therein;

the step of carrying out pre-cracking, crushing and excavating construction on the advanced support body by adopting a hydraulic splitting rod according to the extending direction of the tunnel comprises the following steps:

according to the extending direction of the tunnel, the hydraulic splitting rod is adopted to presplitting and crushing the megarock;

and crushing and excavating the advanced support body by adopting a crushing head.

The invention has the following beneficial effects:

according to the technical scheme, the first construction section is excavated to form the first tunnel face, when the excavation length of the first tunnel face from the second construction section is a preset distance, the first tunnel face is excavated in an expanding mode to form the second tunnel face, the second tunnel face is constructed towards the second construction section to form the advanced support body in the geological body, the advanced support body is subjected to the pre-splitting crushing excavation construction by adopting the hydraulic splitting rod according to the extending direction of the tunnel, when the tunnel is faced with the condition that the tunnel passes through the existing building, the excavation construction can be carried out in a mode of not using a blasting method or a shield method any more, the pre-splitting crushing construction mode of the advanced support body is adopted, disturbance to the existing building in the construction process is avoided, the safety is effectively improved, the problem that the existing tunnel is influenced if the excavation method is adopted when the tunnel passes through the existing building, the tunnel is not subjected to the safety is solved, and if the tunnel is excavated by adopting the blasting method, the safety is not influenced, and the tunnel construction cost is high in the prior art.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of an exemplary tunnel construction method of the present invention;

fig. 2 is a flowchart of step S100 illustrated in fig. 1;

fig. 3 is a flowchart of step S300 illustrated in fig. 1;

fig. 4 is a flowchart of step S320 illustrated in fig. 3;

fig. 5 is a flowchart of step S400 illustrated in fig. 1;

fig. 6 is a flowchart of step S410 illustrated in fig. 5.

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the mechanisms in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is correspondingly changed.

In the present invention, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" as it appears throughout includes three parallel schemes, for example "A and/or B", including the A scheme, or the B scheme, or the scheme where A and B are satisfied simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.

The inventive concept of the present invention is further elucidated below in connection with some embodiments.

The invention provides a tunnel construction method, which is used for constructing a tunnel entering section of a tunnel shallow buried under an existing building, wherein the tunnel entering section is provided with a first construction section and a second construction section buried under the existing building along the length direction of the tunnel;

the tunnel construction method comprises the following steps:

s100, excavating and constructing a first construction section in a preset construction area to form a first tunnel face;

s200, when the excavation length of the first tunnel face from the second construction section is a preset distance, performing excavation expansion construction on the rest first construction sections on the first tunnel face to form the second tunnel face; the excavation area of the second face is larger than that of the first face;

it should be specifically and explicitly stated that, in this embodiment, the preset distance is 5m, and the edge position of the second tunnel face is an outward expansion of 50cm from the edge position of the first tunnel face.

S300, performing middle pipe shed construction on the second tunnel face towards the second construction section so as to form an advanced support body in the geological body;

s400, carrying out pre-splitting crushing excavation construction on the advanced support body by adopting a hydraulic splitting rod according to the extending direction of the tunnel.

In some embodiments, according to a preset requirement, performing excavation construction on a first construction section in a preset construction area to form a first face, including:

s110, excavating and constructing the first construction section in a preset construction area to obtain a section to be supported;

s120, installing an arch frame in the section to be supported to form a first tunnel face.

In some embodiments, after the step of installing the arch in the section to be supported to form the first face, the method further comprises:

s130, hole site lofting is carried out on the first tunnel face, and a plurality of first drilling holes are formed;

and S140, sequentially welding hole site locating frames on all the first drilling holes.

In some embodiments, after the step of welding the hole site locator frame on all of the first bores in sequence, further comprising:

s150, enabling the canopy machine to be located on the first tunnel face;

s160, sequentially drilling all the first drilling holes with a pipe shed machine to form a first pipe shed.

In some embodiments, after the step of sequentially drilling all the first bores with the pipe-cap machine to form the first pipe cap, further comprising:

s170, excavating construction is carried out on the first face, and the distance between the first face and the second construction section is obtained.

In some embodiments, after the step of performing the excavation construction on the first face and obtaining the distance between the first face and the second construction section, the method further includes:

and continuing to excavate until the distance between the first tunnel face and the second construction section is the preset construction distance when the distance between the first tunnel face and the second construction section is greater than the preset distance, and performing the step of expanding excavation construction on the first tunnel face and the rest of the first construction section to form the second tunnel face when the excavation length of the first tunnel face from the second construction section is the preset distance.

In some embodiments, performing a medium pipe shed construction at the second face toward the second construction section to form a lead support within the geologic volume, comprising:

s310, drilling a plurality of holes in a second construction section of the second tunnel face facing the front of the current tunnel face;

s320, respectively installing the guide pipes with corresponding preset lengths in all the holes;

s330, grouting all the guide pipes to obtain a pipe shed so as to form an advanced support body in the geological body.

In some embodiments, the step of installing the conduits having the corresponding preset lengths in all the holes respectively includes:

s321, respectively installing pipe joints with a first length in all holes;

s322, lengthening the corresponding pipe joint according to the preset drilling depth to obtain the corresponding guide pipe with the preset length.

In some embodiments, according to the extending direction of the tunnel, the step of pre-splitting, crushing and excavating the advanced support body by adopting a hydraulic splitting rod includes:

s410, pre-cracking and crushing the advanced support body by adopting a hydraulic splitting rod according to the extending direction of the tunnel to form a body to be excavated;

s420, crushing and excavating construction is carried out on the body to be excavated by adopting the crushing head.

In some embodiments, the geologic volume has megalitters formed therein;

according to the extending direction of the tunnel, the step of pre-splitting, crushing and excavating construction is carried out on the advanced support body by adopting a hydraulic splitting rod, and the method comprises the following steps:

s411, pre-cracking and crushing the megarock by adopting a hydraulic splitting rod according to the extending direction of the tunnel;

s412, crushing and excavating the advanced support body by adopting a crushing head.

In some exemplary embodiments, a highway one-term engineering tunnel under construction by a unit of three companies is designed as a two-way four-lane split highway tunnel, with a left line full length of 2115m. The data from the survey show: the left line import section and the right line import section penetrate through the collapse accumulation body, meanwhile, the tunnel passes through the national road G, resident houses on two sides of the national road are dense, and the burial depth above the vault is about 30m. The collapse slope body of the tunnel entrance section is widely distributed, and is distributed from the slope toe below the tunnel entrance to the middle part of the slope, and the slope toe is relatively gentle; the plane is in an irregular fan shape, the longitudinal slope is about 190m long and the width is about 140m. The trailing edge elevation was 460m and the leading edge elevation was 380m. The planar area is about 28×103m2. The drilling reveals that the maximum thickness of the middle part of the slope body is larger than 42.2m, and the slope body mainly comprises broken slope aggregate stones, broken stones and clay soil, and manual filling (filling of national road beds) is partially covered. The total volume was about 7.0X104 m3. Slope direction 315 deg, natural topography slope angle 19-21 deg, thicker soil mass at front edge and steep topography at rear edge. The underlying bedrock is a two-fold system (P2 q) limestone, the occurrence is 350 DEG & lt 45 DEG, and the slope angle of the bedrock surface is similar to the terrain; the bedrock at the upper part of the slope at the entrance to the cave is exposed, is in the shape of a scarp, has steeper terrain and loose overall covering layer.

The strong support ensures safety. The method is characterized in that phi 89mm self-advancing middle pipe shed advanced support is adopted for the shallow reserved pipe shed room of the pile body, I22b I-steel arch frames are adopted, C25 shotcrete primary support with the thickness of 28cm is adopted, phi 42 grouting anchor pipes are adopted for reinforcing the tunnel circumference, and the like, so that the construction safety is guaranteed.

The construction speed is high. The self-feeding pipe shed is formed at one time, and the pipe shed does not need to be punched and then installed; the hydraulic splitting rod is adopted to be matched with the crushing head for excavation, so that the efficiency is improved more than that of single crushing head excavation.

The cost is reduced. The splitting rod is utilized to split, so that the excavating time of the crushing head is shortened to a large extent, and the investment of mechanical cost is reduced.

The construction period is saved. The self-feeding pipe shed and the hydraulic splitting rod are adopted for splitting, so that the construction time is reduced, the efficiency is improved, and the construction period is saved by about 90 days.

The surrounding rock disturbance is small, and the noise disturbance is small. The mechanical excavation is adopted, so that disturbance to surrounding rock is reduced to the greatest extent, safety and reliability are realized, blasting noise is reduced, and disturbance to people is prevented.

The construction method is suitable for construction of the similar pile body shallow buried tunnel under the existing road or house.

The Hamei HM90AC crawler-type tunnel pipe shed drilling machine is adopted to construct a self-feeding middle pipe shed, the excavation section is enlarged by 5m in advance according to the required operation space of the drilling machine, and the normal section arch centering is tightly attached to the tunnel face to be used as a middle pipe shed construction guide frame for construction. When the large stone disclosed by the excavation is difficult to crush, the hydraulic splitting rod is adopted to crack, so that the excavation efficiency of the crushing head is improved.

The V-stage surrounding rock collapse slope integrated section at the entrance of a certain tunnel has main stratum lithology of block stones, the individual block stones have larger volumes, and fine soil is filled between the block stones. Due to special geology and underpass G, the three-step reserved core soil non-explosive excavation method is finally adopted to reduce the excavation disturbance to the greatest extent. The method is firmly and steadily played according to the principles of 'early forecasting, pipe advance, non-blasting, short footage, strong support, early closing and duty measurement'.

Construction of a pipe shed working room: the pipe shed in the hole is subjected to the influence of the operation space, and the pipe shed working chamber with the length of at least 5m is reserved in construction in consideration of the operation space required by pipe shed drilling and pipe shed pipe conveying. According to the design drawing and the selected pipe shed drilling machine size, the section of the excavation outline is gradually increased within the range of 5 meters in front of the self-fault, and is gradually expanded by 50cm on the basis of the design of the excavation section, so that the section is the starting point section of the 1 st ring construction of the pipe shed.

Positioning and guiding arch frame installation: after the construction of the pipe shed working chamber is completed, the normal section arch centering is tightly attached to the tunnel face and is used as a middle pipe shed construction guide frame. And the next step is to measure and loft, accurately discharge the hole site of each middle pipe shed, weld positioning steel bars on two sides of the hole site by phi 22 steel bars, ensure that the drill bit can smoothly pass through the hole site, and weld two ends of the positioning steel bars on the guide frame and the last arch frame of the pipe shed room to play a role in positioning and guiding.

And (3) construction of a middle pipe shed: the pile body section adopts a middle pipe shed with the outer diameter of 89mm and the thickness of 6.0mm as an advance support, the single length is 10m, the circumferential spacing is 40cm, the external insertion angle is 10-15 degrees, the longitudinal spacing between the pile body section and the next ring of advance support is 6m, and the lap joint length is not less than 3m. Grouting cement slurry cement water-cement ratio: 0.8, grouting pressure: 1.0MPa.

And (5) measuring and rechecking the positioning ribs of the guide frame, and positioning the drilling machine.

According to the diameter and the length of the self-advancing tunnel shed, a HameHM 90AC crawler-type tunnel shed drilling machine is adopted. And installing a guide rail and a drilling machine according to the central line and the angle of each pipe shed.

Installing a pipe shed and a drill bit: after the drilling machine is positioned, the special drill bit and the pipe shed are connected, and the air pipe on the drilling machine is connected.

Drilling of a pipe shed: in order to ensure the direction, gradient and precision of the storage shed, technicians need to measure at any time and adjust the angle of the drilling machine so as to review the design and specification requirements.

And (3) lengthening the pipe shed: the 10m long pipe shed is formed by connecting one section 4m and two sections 3m. After the first section 4m pipe shed is drilled in place, the second section 3m long pipe shed is connected by using a special connecting sleeve for the pipe shed, the third section 3m is connected by using a connecting sleeve after the pipe shed is continuously drilled in place, and the drilling is completed after the pipe shed is continuously drilled in place. In order to ensure that the pipe-shed joints are not on one section, the adjacent two pipe-shed pipes are alternately constructed by adopting 3m+4m+3m.

And (5) removing the drilling machine: after the pipe shed drills in place, the drill clamping device is locked, the drilling machine is reversed, the pipe shed is disassembled from the connecting sleeve of the drilling machine, and the drilling machine is removed. And continuing drilling the lower root canal shed.

Grouting is started by connecting grouting equipment: the grouting joint is rotationally arranged at the tail part of the pipe shed, a grouting pipeline and a grouting pump are connected, grouting is started when slurry (pure cement slurry, water cement ratio of 0.8) is prepared, and grouting pressure is as follows: 1.0MPa.

And (3) excavating a hole: because a certain tunnel import passes through national roads and peripheral houses downwards, and the area is distributed with miscellaneous fill, the side close to the opening is a national road subgrade lower side slope rubble retaining wall. Tunnel excavation disturbance easily causes vault collapse and stack collapse, endangering the safety of national road driving on the top of a slope and resident houses. In order to reduce the disturbance of the excavation of the tunnel body to the stacking body to the greatest extent, a hydraulic splitting rod is adopted to punch larger stones to be split, and then the larger stones are delivered out by a crushing head splitting trolley.

The hydraulic splitting machine adopts a single-oil cylinder double-rod type, the rod body phi is 100mm, the maximum jacking distance is 40mm, and the splitting force is 1500 KN/branch. The existing pipe shed machine is utilized for drilling, the aperture is 110mm, the depth of the hole is 1m, the distance between the holes is controlled to be 50 cm-80 cm according to rocks with different strengths, and the distance between the holes and the free surface is 50cm.

Table 1 construction labor organization for tunnels

The pile tunnel excavation construction is mainly made of a section steel arch frame and a self-feeding pipe shed, wherein the section steel arch frame is intensively processed by a steel bar processing factory, and is distributed to a tunnel portal material transfer warehouse through an automobile crane in a single-position bundling mode, and inspection acceptance system is strictly executed every time, and the inspection design and the standard requirement can be put in warehouse.

Table 2 tunnel primary materials schedule

Sequence number

Component name

Material name

Specification and model

Unit (B)

Quantity of

Construction site

1

Profile steel arch centering

I-steel

I22b

t

293.2

Primary support

2

Middle pipe shed

Pipe shed

Φ89mm

m

15750

Advanced support

3

Reinforcing steel bar net sheet

HPB300

Φ8mm,20×20cm

t

28.1

Primary support

The type selection of equipment is an important factor influencing the engineering progress and the engineering quality, and in order to ensure that the project can finish tasks on schedule, quality guarantee and security, the project selects equipment suitable for on-site operation according to the on-site actual conditions and the construction quality requirements. The equipment and tool configurations are shown in table 3.

TABLE 3 Main construction machinery

Table 4 actual measurement project of pipe shed

Table 5 actual measurement of excavation of shaft

Project department security checks are organized once a month; project site safety inspection is organized more than once a week; team safety checks are performed daily. In the daily construction production process, each level of safety supervisor is responsible for carrying out daily inspection and supervision.

The security department can carry out professional security check and irregular security check according to the requirements of the superior and local governments and the requirements and the change of seasons of construction production with the related departments.

For key parts and important links, the security department needs to implement special person reinforcement monitoring, and the project department performs special key inspection at least once a month.

Unsafe factors are found in the safety inspection, and the safety inspection must be performed in a 'setting' (setting and changing measures, setting and changing responsibilities and setting and changing periods) and the safety management personnel at each level list details, and the numbers are eliminated one by one. The company security department can be reported to assist in solving the problem by the help of the company and other units.

The problem to be detected constitutes the accident potential, and the accident potential modification degree must be strictly executed.

The security inspection must be carried out by combining self-inspection with mutual inspection and combining inspection with rectification.

The construction passageway sprays water back and forth in the morning, in the middle and at the evening, shortens the period and the pollution range of dust pollution, and furthest reduces the dust quantity. Meanwhile, the construction pavement is regularly maintained and cleaned, so that good road conditions are ensured;

a vehicle for transporting bulk dust-containing material is covered with a tarpaulin to prevent the material from flying. The transport vehicle is strictly forbidden to overload and cannot be leaked along the way.

The management of the construction machinery is finished, the oil leakage is avoided, and the waste engine oil cannot be dumped randomly. So as to prevent and treat polluted water resources and destroy living environment of wild animals and plants.

Because of the dense surrounding residents, the working procedure time is reasonably adjusted according to the progress of engineering, and the use of high-noise and high-power equipment at night is forbidden.

The construction method successfully solves the technical problem of rapid construction of the existing national road when the large stone pile body is penetrated under the shallow tunnel. The middle pipe shed advanced support is adopted, and the hydraulic splitting machine is matched with the crushing head for mechanical excavation, so that the construction is convenient, the speed is high, and the safety and the reliability are realized.

The construction method is used for safely and efficiently completing the construction of the stack body penetrating through the national road section, and the construction is completed about 90 days earlier than the planned construction period. The construction process does not influence national road traveling and life traveling of surrounding residents. The method has the advantages that the local government and owners and supervision units are uniformly and well appreciated, good reputation and image are established for the three companies of the middle-iron twenty-first company in the construction of the Yuxiang expressway compound line project, and good social benefit is created.

The construction method is simple and easy to operate, improves the construction efficiency and shortens the construction period. Because the tunnel is excavated by non-blasting machinery, disturbance is reduced to the greatest extent, and blasting noise is avoided to disturb people; the mechanical excavation is clean and environment-friendly, pollution-free to surrounding natural environments is avoided, environment-friendly construction is truly achieved, high evaluation of owners and environment-friendly departments is achieved, no environment-friendly punishment and complaints of disturbing people are avoided in the construction process, and good environment-friendly benefits are achieved.

The foregoing description is only of the optional embodiments of the present invention, and is not intended to limit the scope of the invention, and all the equivalent structural changes made by the description of the present invention and the accompanying drawings or the direct/indirect application in other related technical fields are included in the scope of the invention.

Claims

1. The tunnel construction method is characterized in that the tunnel construction method is used for constructing a tunnel entering section of the tunnel shallow buried below an existing building, and the tunnel entering section is provided with a first construction section and a second construction section buried below the existing building along the length direction of the tunnel;

the tunnel construction method comprises the following steps:

2. The tunnel construction method according to claim 1, wherein the step of performing excavation construction on the first construction section in a preset construction area according to a preset requirement to form a first face comprises:

3. The tunnel construction method according to claim 2, wherein after the step of installing an arch in the section to be supported to form the first face, further comprising:

4. A tunnel construction method according to claim 3, further comprising, after said step of welding hole site spacers sequentially on all of said first boreholes:

the pipe shed machine is located on the first tunnel face;

5. The tunnel construction method according to claim 4, further comprising, after the step of sequentially drilling all the first drill holes with the pipe-cap machine to form a first pipe cap:

6. The tunnel construction method according to claim 5, further comprising, after the step of performing excavation construction on the first face and obtaining a distance between the first face and the second construction section:

7. The tunnel construction method according to any one of claims 1 to 6, characterized in that the step of performing a medium tunnel construction at the second face toward the second construction section to form a pre-support body in the geological volume comprises:

8. The tunnel construction method according to claim 7, wherein the step of installing the pipes having the corresponding preset lengths in all the holes, respectively, comprises:

respectively installing pipe joints with a first length in all the holes;

9. The tunnel construction method according to any one of claims 1 to 6, wherein the pre-splitting, crushing and excavating the advance support body by using a hydraulic splitting rod according to the extending direction of the tunnel comprises:

10. The tunnel construction method according to claim 9, wherein the geologic body has a megarock formed therein;