CN218911435U

CN218911435U - Half-cover-excavated foundation pit cover plate supporting structure suitable for non-horizontal topography condition

Info

Publication number: CN218911435U
Application number: CN202222038899.9U
Authority: CN
Inventors: 王健宏; 张慧玲; 王宏超; 熊国兴; 陈昂
Original assignee: China Railway Eryuan Engineering Group Co Ltd CREEC
Current assignee: China Railway Eryuan Engineering Group Co Ltd CREEC
Priority date: 2022-08-03
Filing date: 2022-08-03
Publication date: 2023-04-25
Anticipated expiration: 2032-08-03

Abstract

A half-cover-excavated foundation pit cover plate supporting structure suitable for non-horizontal terrain conditions is used for guaranteeing the safety of a foundation pit and meeting the traffic requirements of urban arterial roads during foundation pit construction. The top ends of the left continuous wall and the right continuous wall are fixedly connected with left crown beams and right crown beams with different top surface elevations respectively, at least one row of upright posts are arranged between the left continuous wall and the right continuous wall, longitudinal connecting beams are arranged between the upright posts and the right crown beams on the passing side along the transverse interval, transverse connecting beams are arranged between the upright posts and the longitudinal interval, each longitudinal connecting beam and each transverse connecting beam are fixedly connected at staggered nodes to form a horizontal reticular structure, the beam ends of each transverse connecting beam on the right side of the reticular structure are fixedly connected with the right crown beams, and the left side of the reticular structure is fixedly connected with the upright posts at the staggered nodes. Diagonal braces are longitudinally arranged between the upright posts and left crown beams on the non-passing inner side of the vehicle at intervals, the left ends of the diagonal braces are fixedly connected with the left crown beams, the right ends of the diagonal braces are fixedly connected with the net-shaped structure at the positions where the upright posts are arranged, and pavement cover plates are fixedly arranged on the top surfaces of the net-shaped structure.

Description

Half-cover-excavated foundation pit cover plate supporting structure suitable for non-horizontal topography condition

Technical Field

The utility model relates to civil engineering, in particular to a half-cover-excavated foundation pit cover plate supporting structure suitable for non-horizontal terrain conditions.

Background

In recent decades, the development of large underground spaces in large cities in China is rapid, and a large number of foundation pit engineering construction projects with complex technology are developed. At present, a half-cover excavation method is often adopted in the foundation pit construction of a subway station below an urban trunk road, the influence of the foundation pit construction on traffic can be reduced by constructing a part of cover plate pavement system, the construction progress can be accelerated by non-cover plate side excavation, and the engineering economic investment is reduced. However, the foundation pit structures are designed according to the horizontal topography condition, and the foundation pit sites are often non-horizontal topography, i.e. the surface elevations on the two sides of the foundation pit are inconsistent.

Generally, aiming at the situation that the surface elevation of two sides of a foundation pit is inconsistent, the following methods are mainly adopted: (1) The site is cleaned, so that the elevation of the earth surface at two sides of the foundation pit is equivalent, and then the foundation pit is designed according to the conventional horizontal topography condition, but the earth and stone excavation and filling amount is large, the influence on the surrounding environment is very large, and the foundation pit is not suitable for urban environment; (2) And the two sides of the foundation pit are provided with different-height enclosure structures which are basically flush with the ground surface of the adjacent side, and the safety of the foundation pit structure is ensured by providing an inclined straight support or anchor rod (cable). However, the above structure fails to provide conditions for the construction of the cover plate, and cannot effectively solve the traffic problem of the traffic artery, and in addition, the application of the anchor rod (cable) is limited in urban environments. Therefore, how to make up for the lack of design experience of the cover plate supporting structure under the condition that the surface elevation of the two sides of the half-cover excavated foundation pit is inconsistent is a problem to be solved in the technical field of foundation pit engineering at present.

Disclosure of Invention

The utility model aims to solve the technical problem of providing a half-cover-excavated foundation pit cover plate supporting structure suitable for non-horizontal topography conditions, so as to make up for the defect of foundation pit structural design experience under the condition that the surface elevation of two sides of the half-cover-excavated foundation pit is inconsistent, ensure the safety of the foundation pit and meet the traffic requirement of urban arterial roads during the construction of the foundation pit.

The technical scheme adopted for solving the technical problems is as follows:

the utility model relates to a half-cover-excavated foundation pit cover plate supporting structure suitable for non-horizontal terrain conditions, which comprises a left continuous wall and a right continuous wall for providing a containment for the transverse side wall of a foundation pit, and is characterized in that: the top ends of the left continuous wall and the right continuous wall are fixedly connected with left crown beams and right crown beams with different top surface elevations respectively, at least one row of upright posts are arranged between the left continuous wall and the right continuous wall, longitudinal connecting beams are arranged between the upright posts and the right crown beams on the passing side along the transverse interval, transverse connecting beams are arranged between the upright posts and the right crown beams on the passing side along the longitudinal interval, each longitudinal connecting beam and each transverse connecting beam are fixedly connected at staggered nodes to form a horizontal reticular structure, the beam ends of each transverse connecting beam on the right side of the reticular structure are fixedly connected with the right crown beams, and the left side of the reticular structure is fixedly connected with the upright posts at the staggered nodes; diagonal braces are longitudinally arranged between the upright posts and the left crown beams on the non-passing inner side of the vehicle at intervals, the left ends of the diagonal braces are fixedly connected with the left crown beams, and the right ends of the diagonal braces are fixedly connected with the net-shaped structure at the positions where the upright posts are arranged; and a pavement cover plate is fixedly arranged on the top surface of the net-shaped structure.

The beneficial effects of the utility model are mainly shown in the following aspects:

1. the transverse connecting beams and the diagonal braces form a first channel support of the foundation pit together, and the first channel support is a broken line type support, can effectively support a road cover plate, ensure road traffic, control foundation pit deformation and ensure safety of foundation pit excavation;

2. the position and the width of the pavement cover plate can be flexibly set according to traffic requirements, and the pavement cover plate has strong applicability to ensuring traffic of the pavement when the foundation pit is constructed by half cover excavation under the condition of non-horizontal topography;

3. the bottom of the pavement cover plate is provided with a proper number of longitudinal connecting beams and upright posts, so that the construction condition and the safety problem of the pavement cover plate by the half-cover digging method under the non-horizontal topography condition are reasonably solved, and the advantages of the half-cover digging method are fully exerted under the non-horizontal topography condition.

Drawings

The specification includes the following six figures:

FIG. 1 is a schematic cross-sectional view of an embodiment 1 of a half-cap foundation pit deck support structure of the present utility model adapted for use in non-horizontal terrain conditions;

FIG. 2 is a schematic plan view of an embodiment 1 of a half-cap foundation pit cover plate support structure of the present utility model adapted for use in non-horizontal terrain conditions;

FIG. 3 is a schematic cross-sectional view of an embodiment 2 of a half-cap foundation pit deck support structure of the present utility model adapted for use in non-horizontal terrain conditions;

FIG. 4 is a schematic plan view of an embodiment 2 of a half-cap foundation pit cover plate support structure of the present utility model adapted for use in non-horizontal terrain conditions;

FIG. 5 is a schematic cross-sectional view of an embodiment 3 of a half-cap foundation pit deck support structure of the present utility model adapted for use in non-horizontal terrain conditions;

FIG. 6 is a schematic plan view of an embodiment 3 of a half-cap foundation pit cover plate support structure of the present utility model adapted for use in non-horizontal terrain conditions;

the components and corresponding indicia are shown: left side diaphragm wall 11, left crown beam 12, right side diaphragm wall 13, right crown beam 14, upright 15, road deck 20, longitudinal tie beam 21, transverse tie beam 22, diagonal bracing 23.

Detailed Description

The utility model will be further described with reference to the drawings and examples.

Referring to fig. 1 and 2, a half-cap excavated foundation pit cover plate supporting structure suitable for non-horizontal topography conditions of the present utility model includes left side continuous wall 11 and right side continuous wall 13 that provide containment for the lateral side walls of the foundation pit. The top ends of the left continuous wall 11 and the right continuous wall 13 are fixedly connected with left crown beams 12 and right crown beams 14 with different top surface elevations respectively, at least one row of upright posts 15 is arranged between the left continuous wall 11 and the right continuous wall 13, longitudinal connecting beams 21 are arranged between the upright posts 15 and the right crown beams 14 on the passing side along the transverse interval, transverse connecting beams 22 are arranged between the upright posts 15 and the right crown beams 14 on the passing side along the longitudinal interval, each longitudinal connecting beam 21 and each transverse connecting beam 22 are fixedly connected at staggered nodes to form a horizontal net structure, the beam ends of the right transverse connecting beams 22 of the net structure are fixedly connected with the right crown beams 14, and the left side is fixedly connected with the upright posts 15 at the staggered nodes. Diagonal braces 23 are longitudinally arranged between the upright posts 15 and the left crown beams 12 on the non-passing inner side of the vehicle at intervals, the left ends of the diagonal braces 23 are fixedly connected with the left crown beams 12, and the right ends of the diagonal braces are fixedly connected with the net-shaped structure at the positions where the upright posts 15 are arranged; a stationary pavement cover 20 is mounted on the top surface of the mesh structure. The road load is transmitted to the left crown beam 12 and the right crown beam 14 through the transverse connecting beams 22 and the diagonal braces 23, and is also transmitted to the soil body at the lower part of the foundation pit through the upright posts 15, so that the stability of the road cover plate 20 can be effectively ensured, and the traffic on the road surface during the excavation of the foundation pit is ensured through the road cover plate 20.

Referring to fig. 1, the transverse connecting beam 22 and the diagonal bracing 23 together form a first path support of the foundation pit, which is a broken line type support, can effectively support the pavement cover plate 20, ensure the traffic of the pavement, control the deformation of the foundation pit and ensure the safety of excavation of the foundation pit. The position and the cover plate width of the pavement cover plate 20 can be flexibly set according to traffic requirements, and the pavement cover plate has strong applicability to ensuring traffic of the pavement when the foundation pit is constructed by half cover excavation under non-horizontal terrain conditions.

The utility model makes up the defect of design experience of the cover plate supporting structure under the condition that the surface elevation of the two sides of the half-cover excavation foundation pit is inconsistent, can effectively ensure the safety of the foundation pit, meets the traffic requirement of urban arterial roads, and has strong practicability and popularization significance.

Referring to embodiment 1 shown in fig. 1 and 2, the embodiment is applied to a subway foundation pit engineering of a long sand subway line 4, the elevation of the right side surface of the foundation pit is 77.5m, the elevation of the left side surface of the foundation pit is 74.0m, the elevations of the two side surface of the foundation pit are different by about 3.5m, the elevation of the top of a pavement cover plate 20 is level with the right side surface of the foundation pit, and the elevations of the left crown beam 12 and the right crown beam 14 are equivalent to those of the adjacent side surface of the foundation pit; the excavation width of the foundation pit is 24m, the pavement cover plate 20 adopts a reinforced concrete cover plate with the thickness of 300mm and the width of 12m, the cross section size of the longitudinal connecting beam 21 is 0.8mx1.0m, the cross section sizes of the transverse connecting beam 22, the diagonal bracing 23, the left crown beam 12 and the right crown beam 14 are all 1.0mx1.2m, the structure is C30 reinforced concrete, the upright column 15 adopts a steel pipe column with the diameter phi 609mm, and the wall thickness t=16mm.

In example 1, the width of the pavement slab 20 is equal to 1/2 of the width of the foundation pit, 3 longitudinal tie beams 21 are provided, and the pitch of the longitudinal tie beams 21 is 4m, which is about 1/3 of the width of the pavement slab. The longitudinal connecting beams 21 and the transverse connecting beams 22 are arranged to intersect perpendicularly with each other in a box-like structure. The upright 15 is disposed only at the intersection of the transverse contact beam 22 and the diagonal strut 23.

Example 1 the main construction steps of the site construction are as follows:

1. constructing left continuous wall 11 and right continuous wall 13 as foundation pit supporting structures at the outer edges of the inside of the foundation pit, wherein the elevations of the left continuous wall 11 and the right continuous wall 13 are respectively leveled with the adjacent ground surfaces;

2. determining the construction position of the upright post 15 according to the position and the width of the pavement cover plate 20, and then lofting and construction are carried out;

3. digging earthwork at the top of the enclosure structure, respectively chiseling inferior concrete at the tops of the two side enclosures structure until the heights of the left crown beam 12 and the right crown beam 14 are equal to the heights of adjacent ground surfaces of the left crown beam 12 and the right crown beam 14 and Liang Dingbiao;

4. the longitudinal connecting beam 21 and the transverse connecting beam 22 are grooved, soil above the beam bottom elevation is completely excavated, and templates are erected;

5. grooving by a slope brushing method, excavating all soil above the bottom elevation of the diagonal bracing 23 position, and erecting a template;

6. pouring a longitudinal connecting beam 21, a transverse connecting beam 22 and a diagonal brace 23, and performing one-time pouring molding;

7. and backfilling and leveling soil to the elevation of the bottom of the pavement cover plate 20, and performing construction of the pavement cover plate 20 after erecting a mould.

If the pavement cover 20 is a steel cover, a clamping steel plate should be reserved at the intersection point of the longitudinal connecting beam 21 and the transverse connecting beam 22, and the pavement cover 20 is arranged on the clamping steel plate and is leveled with the right-side ground surface.

Referring to embodiment 2 shown in fig. 3 and 4, the width of the pavement cover 20 of this embodiment is greater than 1/2 of the width of the foundation pit, and due to the traffic flow requirement, the width of the pavement cover 20 is 18m, and 4 longitudinal connecting

beams

21 and 2 upright posts 15 are required to be arranged at the bottom of the pavement cover 20 in the transverse direction of the foundation pit, so as to increase the rigidity of the whole supporting system, ensure that the pavement cover 20 is not deformed too much under the action of the load of the vehicle, and ensure the driving safety and the construction safety of the foundation pit.

Referring to embodiment 3 shown in fig. 5 and 6, the width of the pavement cover 20 of this embodiment is smaller than 1/2 of the width of the foundation pit, and due to the traffic flow requirement, the width of the pavement cover 20 is 6m, when 2 longitudinal connecting beams 21 and 1 upright 15 are transversely arranged at the bottom of the pavement cover 20 in the foundation pit, the pavement cover can be prevented from being deformed too much under the action of the load of the vehicle, and the driving safety and the construction safety of the foundation pit are ensured.

The utility model reasonably solves the construction condition and the safety problem of the half-cover-excavation pavement cover plate under the non-horizontal topography condition by arranging a proper number of longitudinal connecting beams 21 and upright posts 15 at the bottom of the pavement cover plate 20 according to the embodiment 1, the embodiment 2 and the embodiment 3, and fully exerts the advantages of the half-cover-excavation pavement cover plate under the non-horizontal topography condition.

The foregoing is illustrative of the principles of the present utility model in a semi-cover pit cover plate support structure for use in non-horizontal terrain conditions and is not intended to limit the utility model to the specific structure and application scope of the utility model shown and described, but rather to limit the utility model to all corresponding modifications and equivalents which may be resorted to, falling within the scope of the utility model as defined by the appended claims.

Claims

1. The utility model provides a half lid digs foundation ditch apron bearing structure suitable for non-horizontal topography condition, includes left side diaphragm wall (11), right side diaphragm wall (13) that provide the enclosure to the horizontal lateral wall of foundation ditch, characterized by: the top ends of the left continuous wall (11) and the right continuous wall (13) are fixedly connected with left crown beams (12) and right crown beams (14) with different top surface elevations respectively, at least one row of upright posts (15) are arranged between the left continuous wall (11) and the right continuous wall (13), longitudinal connecting beams (21) are arranged between the upright posts (15) and the right crown beams (14) on the passing side along the transverse interval, transverse connecting beams (22) are arranged between the upright posts at the longitudinal interval, each longitudinal connecting beam (21) and each transverse connecting beam (22) are fixedly connected at staggered nodes to form a horizontal net structure, the beam ends of the transverse connecting beams (22) on the right side of the net structure are fixedly connected with the right crown beams (14), and the left side of the net structure is fixedly connected with the upright posts (15) at the staggered nodes; diagonal braces (23) are longitudinally arranged between the upright posts (15) and the left crown beams (12) on the non-vehicle inner side at intervals, the left ends of the diagonal braces (23) are fixedly connected with the left crown beams (12), and the right ends of the diagonal braces are fixedly connected with the net-shaped structure at the positions where the upright posts (15) are arranged; and a pavement cover plate (20) is fixedly arranged on the top surface of the net-shaped structure.

2. A half-cap pit cover plate support structure for use in non-horizontal terrain conditions as claimed in claim 1, wherein: the pavement cover plate (20) is a reinforced concrete cover plate or a steel cover plate.