CN111218938A - Excavation construction method for foundation pit above existing tunnel - Google Patents

Excavation construction method for foundation pit above existing tunnel Download PDF

Info

Publication number
CN111218938A
CN111218938A CN202010014404.1A CN202010014404A CN111218938A CN 111218938 A CN111218938 A CN 111218938A CN 202010014404 A CN202010014404 A CN 202010014404A CN 111218938 A CN111218938 A CN 111218938A
Authority
CN
China
Prior art keywords
construction
foundation pit
excavation
existing tunnel
slope
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010014404.1A
Other languages
Chinese (zh)
Inventor
卢建文
区建峰
蔡庆军
王朝龙
袁光辉
李天隆
李宗阳
邝楚钊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China Construction Eighth Engineering Division Co Ltd
Original Assignee
China Construction Eighth Engineering Division Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China Construction Eighth Engineering Division Co Ltd filed Critical China Construction Eighth Engineering Division Co Ltd
Priority to CN202010014404.1A priority Critical patent/CN111218938A/en
Publication of CN111218938A publication Critical patent/CN111218938A/en
Pending legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00Excavations; Bordering of excavations; Making embankments
    • E02D17/02Foundation pits
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00Excavations; Bordering of excavations; Making embankments
    • E02D17/02Foundation pits
    • E02D17/04Bordering surfacing or stiffening the sides of foundation pits
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00Excavations; Bordering of excavations; Making embankments
    • E02D17/20Securing of slopes or inclines
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00Excavations; Bordering of excavations; Making embankments
    • E02D17/20Securing of slopes or inclines
    • E02D17/202Securing of slopes or inclines with flexible securing means
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D31/00Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D2250/00Production methods
    • E02D2250/003Injection of material

Abstract

The invention provides a foundation pit excavation construction method above an existing tunnel, which is characterized in that excavation of a foundation pit in a protection area range above the existing tunnel is conducted through sectional strip extraction excavation construction, the subway tunnel is prevented from floating upwards due to excavation unloading, the excavation earthwork at the top of the foundation pit is hardened, and a ballast structure is arranged at the bottom of the excavated foundation pit for carrying out stacking and the like, so that the floating upwards of the existing tunnel structure is prevented. The invention solves the problem of how to ensure the safety and stability of the existing tunnel and ensure the rapid advance of the earthwork excavation construction at the upper part of the subway.

Description

Excavation construction method for foundation pit above existing tunnel
Technical Field
The invention relates to the technical field of building construction, in particular to a foundation pit excavation construction method above an existing tunnel.
Background
Along with the rapid development of cities, the engineering construction along the subway and around the subway is increased day by day, the existing tunnel is required to be covered by a building under common conditions, and the earth excavation at the upper part of the subway easily generates great safety risk to the existing tunnel. How to ensure the safety and stability of the operated existing tunnel and ensure the rapid advance of the earth excavation construction at the upper part of the subway is an urgent need to solve the problem.
Disclosure of Invention
In order to overcome the defects in the prior art, a foundation pit excavation construction method above the existing tunnel is provided so as to solve the problem of how to ensure the safety and stability of the existing tunnel and ensure the rapid advance of earthwork excavation construction at the upper part of the subway.
In order to achieve the aim, the foundation pit excavation construction method above the existing tunnel comprises the following steps:
pouring a hardening and reinforcing layer on the earthwork of the existing tunnel;
arranging a foundation pit along the length direction of the existing tunnel and dividing the foundation pit into a plurality of construction sections;
excavating a plurality of construction sections according to a preset sequence, wherein each construction section is excavated to form a bevel slope which inclines forwards along the excavation direction;
grouting and reinforcing the slope of each excavated construction section;
and after each construction section is excavated to the foundation pit bottom elevation, pouring a ballast structure at the foundation pit bottom of each construction section after each excavation is finished.
And further, before the construction section is excavated, dewatering wells are arranged on the periphery of the foundation pit.
Further, the preset sequence is that excavation is carried out from two ends of the foundation pit to the middle of the foundation pit simultaneously.
Furthermore, each construction section is divided into a plurality of construction layers, and the plurality of construction layers are excavated layer by layer when each construction section is excavated.
Furthermore, the two opposite sides of the existing tunnel are respectively provided with a ground connection wall, the upper part of the ground connection wall extends into the foundation pit, and after each construction layer is excavated, the ground connection wall in the construction layer after each excavation is completed is removed.
Further, after the bevel side slope is subjected to grouting reinforcement, a side slope support is laid on the bevel side slope, so that the side slope support is connected with the hardened reinforcing layer.
Further, the step of laying a slope support on the bevel slope comprises:
after the earthwork of each construction layer is excavated, a reinforcing mesh is hung on the inclined slope of each excavated construction layer;
and spraying concrete on the reinforcing mesh sheet to form the side slope support of the construction layer.
Further, after the side slope support is paved, a stacking platform is formed by pouring the side slope support.
Further, the step of pouring a ballast structure at the bottom of the foundation pit of each excavated construction section includes:
constructing a waterproof layer at the bottom of the foundation pit of the construction section;
and pouring a pressure-bearing plate on the waterproof layer.
The method for excavating the foundation pit above the existing tunnel has the advantages that the excavation construction of the foundation pit in the protection area range above the existing tunnel is carried out through sectional strip-pulling excavation construction, the subway tunnel is prevented from floating upwards due to excavation unloading, the excavation earthwork at the top of the foundation pit is hardened, and the ballast structure is arranged at the bottom of the excavated foundation pit for stacking and the like, so that the floating upwards of the existing tunnel structure is prevented.
Drawings
Fig. 1 to 7 are schematic views illustrating steps of a method for excavating a foundation pit above an existing tunnel according to an embodiment of the present invention.
Fig. 8 is a schematic diagram of a sectional delamination breaking of a diaphragm wall according to an embodiment of the present invention.
Fig. 9 is a schematic sectional view of a construction section of a foundation pit according to an embodiment of the present invention.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
Fig. 1 to 7 are schematic diagrams illustrating steps of a method for excavating a foundation pit above an existing tunnel according to an embodiment of the present invention, where fig. 1, 3, 4, 5, and 7 are sectional views in a longitudinal direction of the existing tunnel, fig. 2 and 6 are sectional views in a transverse direction of the existing tunnel, fig. 2 is a transverse view of fig. 1, and fig. 6 is a transverse view of fig. 5. Fig. 8 is a schematic sectional view of a diaphragm wall according to an embodiment of the present invention, and fig. 9 is a schematic sectional view of a construction section of a foundation pit according to an embodiment of the present invention.
Referring to fig. 1 to 9, the present invention provides a method for excavating a foundation pit above an existing tunnel, including the steps of:
s1: and pouring a hardening and reinforcing layer 2 on the earthwork of the existing tunnel 1.
And (5) placing points to position the foundation pit on a construction site.
And after the foundation pit is positioned, pouring a hardening and reinforcing layer 2 on the earthwork of the existing tunnel 1.
The hardening and reinforcing layer can harden the surface layer of the earthwork, the hardening thickness is about 10cm, the safety and the reliability of a hoisting crane station are guaranteed, and rainwater or surface water can be isolated from seeping into the range of the existing tunnel in large quantity to further cause the floating of the existing tunnel.
Specifically, the step of pouring the hardened reinforcing layer 2 on the earthwork of the existing tunnel 1 is to pour concrete on the earthwork of the existing tunnel 1 to be consolidated so as to form the hardened reinforcing layer 2.
Preferably, before concrete is poured on the earthwork of the existing tunnel 1, a steel bar net piece is erected on the earthwork of the existing tunnel 1. After the reinforcing mesh is erected, concrete is poured on the earthwork of the existing tunnel 1, and the concrete wraps the reinforcing mesh to be solidified to form a hardened reinforcing layer of the reinforced concrete, so that the tensile strength of the hardened reinforcing layer is improved, and the hardened reinforcing layer is prevented from being crushed when a large machine is loaded.
In an embodiment, the hardened reinforcing layer is disposed directly above the existing tunnel and along a length of the existing tunnel.
S2: and arranging the foundation pit C along the length direction of the existing tunnel 1 and dividing the foundation pit C into a plurality of construction sections A.
In this embodiment, the foundation pit to be excavated is arranged along the length direction of the existing tunnel, and the width of the foundation pit is greater than that of the existing tunnel. Construction is performed by dividing the foundation pit into a plurality of construction sections in the longitudinal direction of the foundation pit.
S3: and excavating a plurality of construction sections A according to a preset sequence, wherein each construction section A is excavated to form a bevel slope 3 which inclines forwards along the excavation direction.
And before the construction section A is excavated, arranging dewatering wells at the periphery of the foundation pit C. The dewatering control of the existing tunnel and the periphery of the foundation pit is improved through the dewatering well, and the buoyancy of the existing tunnel is reduced.
And after the dewatering well is excavated and laid, excavating from two ends of the foundation pit C to the middle of the foundation pit C simultaneously according to the preset sequence, and respectively excavating a plurality of construction sections A.
The preset sequence can be constructed from the construction sections at two ends of the foundation pit to the middle construction section, and in some embodiments, the construction assembly line of the construction sections is increased while the back-pressure anti-floating effect of the upper earth covering on the existing tunnel is ensured, and the construction period is shortened. For a subway protection area with a long line crossing existing tunnels, construction flow lines among the sections can be properly increased.
In a preferred embodiment, each construction section A is divided into a plurality of construction layers B, and the plurality of construction layers B of each construction section A are excavated layer by layer.
The earthwork excavation height of each construction layer is not more than 2m, namely the height of each construction layer B is not more than 2m, so that the operation height of constructors is guaranteed, and floating caused by rapid unloading of the earthwork on the upper part of the existing tunnel is avoided. By means of layered excavation, the displacement change of the existing tunnel can be observed in time, and therefore corresponding remedial measures can be taken.
S4: and grouting and reinforcing the bevel slope 3.
And grouting and reinforcing the bevel slope 3, and performing high-pressure grouting and consolidation on soil between the existing tunnel and the excavation surface (the bevel slope), so as to resist the displacement of the existing tunnel.
In a preferred embodiment, after each construction layer is excavated, the slope of the construction layer is grouted.
In this embodiment, the two opposite sides of the existing tunnel 1 are respectively provided with the underground diaphragm walls 11, the upper parts of the underground diaphragm walls 11 extend into the foundation pit C, and after each construction layer B is excavated, the underground diaphragm walls 11 in each excavated construction layer B are removed.
The underground diaphragm wall of the existing tunnel is dismantled and divided into a plurality of concrete blocks, the length and height of each block do not exceed 1.5m multiplied by 2m, and the thickness of each block is equal to the thickness of the existing underground diaphragm wall. The condition that the concrete blocks are too heavy and cannot be hoisted through machinery is avoided, and meanwhile, the operation space of personnel is highly met.
Furthermore, the underground diaphragm wall should be dismantled in a static cutting mode, so that disturbance to the existing tunnel caused by a dismantling mode with excessive vibration is avoided. Before static cutting, air drill drilling is adopted at the intersection point of the concrete blocks, so that the static cutting construction condition is met. When cutting, the horizontal cutting seam is firstly started, and then the vertical cutting seam is cut.
When the joint cutting is dismantled in the division of diaphragm wall, should set up horizontal joint cutting and waist under the roof beam if meeting existing support waist roof beam, prevent to topple over and hinder the people during the cutting.
Further, the concrete block of the static force cutting diaphragm wall is drilled with 1-2 hoisting holes in the middle of the diaphragm wall by a drilling machine, iron bolts are penetrated, then snap rings penetrated with steel wire ropes are penetrated into the bolts, and the split blocks are sequentially lifted out of the field by a crane or stacked as counter weights on a constructed pressure support plate and a stacking platform to carry out stacking back pressure on the existing tunnel.
And after the bevel slope 3 is grouted and reinforced, a slope support is laid on the bevel slope 3, so that the slope support is connected with the hardened reinforcing layer 2.
Specifically, the step of laying a slope support on the slope 3 includes:
after the earthwork of each construction layer B is excavated, a reinforcing mesh is hung on the bevel slope 3 of the construction layer after the excavation is finished;
and spraying concrete on the reinforcing mesh sheet to form the slope support of the construction layer B.
After the earthwork of each construction layer is excavated, the slope support construction of the slope is followed in time, so that the integral instability of the slope caused by poor soil quality or sudden rainstorm can be prevented, and the operation safety of subsequent workers is influenced.
And after the side slope support is paved, pouring the side slope support to form a stacking platform. The emergency counterweight is stacked on the stacking platform with the bevel slope, so that the effect of timely back pressure on the existing tunnel is achieved.
The stacking platform can be used for cutting off operation spaces for construction such as underground diaphragm walls and the like for constructors and equipment, so that a construction operation frame with a large number of cutting platforms can be avoided after excavation, construction progress is improved, and operation frame cost is reduced.
S5: and after each construction section A is excavated to the elevation of the bottom C of the foundation pit, pouring a ballast structure 4 at the bottom C of the foundation pit of each excavated construction section A.
Step S5 includes the following steps:
constructing a waterproof layer at the bottom of the foundation pit of the excavated construction section A;
and pouring a pressure-bearing plate on the waterproof layer.
The emergency counterweight is stacked on the pressure-bearing plate, so that the effect of timely back-pressing the existing tunnel is achieved.
And after the ballast structure is finished, starting excavation and pouring construction of the next construction section until all the construction sections finish the excavation and pouring construction of the structure.
Further, the ballast structures of the plurality of construction sections are connected into a whole.
When each construction section A of the foundation pit is excavated to the designed foundation pit bottom elevation, the pressing structure is poured section by section, the construction of the ballast structure is completed as soon as possible, the exposure time of the upper part of the existing tunnel after unloading is shortened, and the anti-floating back pressure effect is achieved.
The foundation pit excavation construction method above the existing tunnel is characterized in that excavation construction is carried out on the foundation pit in the protection area range above the existing tunnel through sectional strip excavation, the subway tunnel is prevented from floating upwards due to excavation unloading, and floating upwards of the existing tunnel structure is prevented and prevented in the modes of hardening excavation earthwork at the top of the foundation pit, arranging a ballast structure at the bottom of the excavated foundation pit for carrying and the like.
Furthermore, the foundation pit excavation construction method above the existing tunnel is used for carrying out layered excavation construction on the foundation pit excavation in the protection area range above the existing tunnel, so that the subway tunnel is prevented from floating upwards due to excavation unloading, and the floating situation of the existing tunnel is monitored by layered excavation to deal with the abnormal situation in time. When the foundation pit is excavated and the diaphragm wall is dismantled, the disturbance to the existing tunnel is greatly reduced, and meanwhile, the mutual synergistic promotion effect is achieved by thinning and closely connecting the excavation of the foundation pit and the dismantling of the diaphragm wall, so that the working efficiency is improved. The floating of the existing tunnel is avoided through modes of hardening, dewatering, pressing the carrier plate, aligning the stacking platform and the like.
It should be noted that the structures, ratios, sizes, and the like shown in the drawings attached to the present specification are only used for matching the disclosure of the present specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions of the present invention, so that the present invention has no technical essence, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.
While the present invention has been described in detail and with reference to the embodiments thereof as illustrated in the accompanying drawings, it will be apparent to one skilled in the art that various changes and modifications can be made therein. Therefore, certain details of the embodiments are not to be interpreted as limiting, and the invention is to be defined by the scope of the appended claims.

Claims (9)

1. A foundation pit excavation construction method above an existing tunnel is characterized by comprising the following steps:
pouring a hardening and reinforcing layer on the earthwork of the existing tunnel;
arranging a foundation pit along the length direction of the existing tunnel and dividing the foundation pit into a plurality of construction sections;
excavating a plurality of construction sections according to a preset sequence, wherein each construction section is excavated to form a bevel slope which inclines forwards along the excavation direction;
grouting and reinforcing the slope of each excavated construction section;
and after each construction section is excavated to the foundation pit bottom elevation, pouring a ballast structure at the foundation pit bottom of each construction section after each excavation is finished.
2. The excavation construction method of the foundation pit above the existing tunnel according to claim 1, wherein before excavation of the construction section, dewatering wells are arranged on the periphery of the foundation pit.
3. The excavation construction method of the foundation pit above the existing tunnel according to claim 1, wherein the predetermined sequence is excavation from both ends of the foundation pit to the middle thereof at the same time.
4. The method of excavating a foundation pit above an existing tunnel according to claim 1, wherein each of the construction sections is divided into a plurality of construction layers, and the plurality of construction layers are excavated layer by layer while each of the construction sections is excavated.
5. The method of claim 4, wherein the underground diaphragm walls are respectively disposed at two opposite sides of the existing tunnel, upper portions of the underground diaphragm walls extend into the foundation pit, and after each of the construction layers is excavated, the underground diaphragm walls in the construction layers after each excavation is removed.
6. The excavation method of the foundation pit above the existing tunnel according to claim 4, wherein after the slope is reinforced by grouting, a slope support is laid on the slope so that the slope support is connected to the hardened reinforcing layer.
7. The excavation construction method of the foundation pit above the existing tunnel according to claim 6, wherein the step of laying a slope support on the sloping slope comprises:
after the earthwork of each construction layer is excavated, a reinforcing mesh is hung on the inclined slope of each excavated construction layer;
and spraying concrete on the reinforcing mesh sheet to form the side slope support of the construction layer.
8. The excavation construction method of the foundation pit above the existing tunnel according to claim 6, wherein a loading platform is formed by pouring the slope support after the slope support is laid.
9. The excavation construction method of the foundation pit above the existing tunnel according to claim 1, wherein the step of casting the ballast structure at the bottom of the foundation pit of the construction section where each excavation is completed comprises:
constructing a waterproof layer at the bottom of the foundation pit of the construction section;
and pouring a pressure-bearing plate on the waterproof layer.
CN202010014404.1A 2020-01-07 2020-01-07 Excavation construction method for foundation pit above existing tunnel Pending CN111218938A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010014404.1A CN111218938A (en) 2020-01-07 2020-01-07 Excavation construction method for foundation pit above existing tunnel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010014404.1A CN111218938A (en) 2020-01-07 2020-01-07 Excavation construction method for foundation pit above existing tunnel

Publications (1)

Publication Number Publication Date
CN111218938A true CN111218938A (en) 2020-06-02

Family

ID=70808855

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010014404.1A Pending CN111218938A (en) 2020-01-07 2020-01-07 Excavation construction method for foundation pit above existing tunnel

Country Status (1)

Country Link
CN (1) CN111218938A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111636493A (en) * 2020-06-12 2020-09-08 北京市政建设集团有限责任公司 Control method for upward floating of existing station in construction of confined water stratum close to foundation pit
CN112252330A (en) * 2020-10-16 2021-01-22 安徽省交通建设股份有限公司 Safety protection system for excavation of existing line subway tunnel by foundation pit and construction method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101250882A (en) * 2008-04-03 2008-08-27 上海市第一建筑有限公司 Method for discharging construction of underground tunnel upper
CN101824824A (en) * 2010-04-30 2010-09-08 南京市市政设计研究院有限责任公司 Construction method of controlling raised deformation of existing buildings under foundation pits through pile slab supporting and protection
CN105862930B (en) * 2016-05-31 2018-05-15 中铁第四勘察设计院集团有限公司 A kind of protection structure to creating existing tunnel below underground engineering
CN109339029A (en) * 2018-09-18 2019-02-15 中国铁路设计集团有限公司 A kind of construction method of existing tunnel top excavation of foundation pit Resistant heave deformation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101250882A (en) * 2008-04-03 2008-08-27 上海市第一建筑有限公司 Method for discharging construction of underground tunnel upper
CN101824824A (en) * 2010-04-30 2010-09-08 南京市市政设计研究院有限责任公司 Construction method of controlling raised deformation of existing buildings under foundation pits through pile slab supporting and protection
CN105862930B (en) * 2016-05-31 2018-05-15 中铁第四勘察设计院集团有限公司 A kind of protection structure to creating existing tunnel below underground engineering
CN109339029A (en) * 2018-09-18 2019-02-15 中国铁路设计集团有限公司 A kind of construction method of existing tunnel top excavation of foundation pit Resistant heave deformation

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
上海市土木工程学会等: "《城市交通隧道工程最新技术2003上海国际隧道工程研讨会论文集》", 31 October 2003 *
陆新征: "《第26届全国结构工程学术会议论文集 第1册》", 30 September 2017 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111636493A (en) * 2020-06-12 2020-09-08 北京市政建设集团有限责任公司 Control method for upward floating of existing station in construction of confined water stratum close to foundation pit
CN112252330A (en) * 2020-10-16 2021-01-22 安徽省交通建设股份有限公司 Safety protection system for excavation of existing line subway tunnel by foundation pit and construction method

Similar Documents

Publication Publication Date Title
CN104612162B (en) A kind of Deep Foundation Pit of Metro Stations excavation construction method
CN102505695B (en) Construction method for deep foundation pit of three-dimensional garage
CN102031784B (en) Slope protection pile pouring and cable bolting construction method for deep foundation pit
CN102720140B (en) Large-span prestress concrete continuous beam deepwater pier construction process
CN101838968B (en) Double track bridge construction process crossing existing railway operational lines
CN101691751B (en) Construction method for making ultra-long artificial excavating pile penetrate cave and ultra-long pile penetrating cave
CN106120839B (en) A kind of construction technology of off-lying sea blower foundation embedded rock pile
CN108060683A (en) A kind of middle weathering geology top-down construction method
CN111218938A (en) Excavation construction method for foundation pit above existing tunnel
CN106968256A (en) Foundation ditch assembled steel trestle construction method
CN103938634B (en) A kind of deep foundation pit supporting structure and construction method
CN105839946A (en) Brick-concrete structure building lifting add-layer method
CN111576431A (en) Excavation method for foundation pit of four-layer subway station
CN111236241B (en) Weak water-rich stratum subway foundation pit reinforcing excavation method based on half-cover excavation method
CN109610473A (en) A kind of construction method of the large-scale pool structure foundation pit supporting system of municipal administration
CN108301440A (en) With waterproof, the underground pipe gallery construction method of drain function
CN215211056U (en) Assembled multilayer inner supporting structure
CN111101540B (en) Construction method for passing existing electric power tunnel on open cut tunnel
CN110863496B (en) Method for replacing, supporting, excavating and constructing arch center foundation by concrete supporting in stone-filled island building area
CN110258600B (en) Vertical cofferdam construction method suitable for deepwater area
CN109024670B (en) Underground comprehensive pipe gallery protection and reinforcement system penetrating through buried high-voltage cable and reinforcement method
CN110700116A (en) Overpass reverse construction method suitable for loess area
CN108571010B (en) Method for integrating open cut method engineering prefabricated main structure and supporting structure
CN204551485U (en) Semi-inverse method throws support formula foundation ditch combined enclosure structure
CN211200424U (en) Splicing prefabricated mountain slope supporting structure

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination