Supporting structure for subway station foundation pit
Technical Field
The utility model relates to a supporting structure for a subway station foundation pit, and belongs to the technical field of subway construction.
Background
At present, subway construction is carried out on large scale in large and medium-sized cities in China, subway stations are usually located in densely-built areas, the surrounding environment is complex, and control over a foundation pit enclosure structure and a support system is required to be strengthened in order to guarantee stability of surrounding buildings and underground pipelines, construction safety in a foundation pit and stability of the foundation pit. For example, shotcrete retaining walls, underground continuous walls, and columnar cast-in-place bored piles may be used to form foundation pit wall enclosures to prevent outside soil from collapsing.
After the building enclosures are constructed, the transverse supports are constructed at different height positions between the building enclosures on the two sides, so that the building enclosures on the two sides are connected to form a foundation pit supporting structure with high supporting rigidity and reliable connection, and the situation that the building enclosures on the two sides incline towards the inner side of the foundation pit when an underground engineering main structure is constructed in the foundation pit is prevented. In the process of constructing the main structure of the underground engineering, a foundation pit bottom plate is poured at the bottom of the foundation pit, then side walls are constructed on the side walls of the foundation pit, a structural top plate is constructed on the top of the side walls, and finally, the earthwork of the top plate is backfilled. In the construction process of the side wall from bottom to top, the transverse support between the enclosing structures on the two sides needs to be gradually detached. At present, the cross brace is used as a temporary structure, is mostly formed by casting concrete on site at present, has the characteristics of high rigidity, small deformation, good pressure resistance and the like, and has the defects of complicated formwork support, high casting cost, low speed, large later-stage chiseling workload and incapability of recycling.
The above description is included in the technical knowledge of the inventors, and does not necessarily constitute a prior art.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the problems in the prior art, and provides a supporting structure for a subway station foundation pit, which has high overall strength and short construction time, and part of the structure can be recycled.
The utility model adopts the following technical scheme to realize the purpose:
a bearing structure for subway station foundation ditch includes:
the enclosure structure is arranged by being attached to the wall of the foundation pit and is formed by a plurality of filling piles arranged at intervals;
the crown beam is horizontally connected with the pile tops of all the cast-in-place piles;
the system comprises a plurality of wales, a plurality of pile bodies, a plurality of filling piles and a plurality of connecting pipes, wherein the wales are horizontally connected with the pile bodies of the filling piles and are formed by cast-in-place concrete;
the horizontal connection is between the crown beam and the horizontal connection is between the waist beams, each horizontal support structure is formed by connecting a plurality of precast concrete supports, and the precast concrete supports, the precast concrete supports and the crown beams and the precast concrete supports and the waist beams are respectively connected through connecting pieces.
Optionally, each connector comprises:
the connecting plates are used for spanning between the precast concrete supports, between the precast concrete supports and the crown beam or between the precast concrete supports and the waist beam;
the bolt groups are prefabricated on the periphery of the precast concrete support end part, the top of the crown beam, the top of the waist beam and the bottom of the waist beam, and the bolt groups penetrate through bolt holes in the corresponding connecting plates and then are fixedly connected with nuts.
Optionally, a cast-in-place concrete section is filled between the precast concrete support and the crown beam or the waist beam, the cast-in-place concrete section is formed in a cavity defined by the connecting piece, and the cast-in-place concrete section and the waist beam are integrally formed.
Optionally, the crown beam is formed on the top of each cast-in-place pile by cast-in-place concrete.
Optionally, each bolt group includes a base and a plurality of bolts fixed on the base.
Benefits of the present application include, but are not limited to:
the support structure for the subway station foundation pit, provided by the utility model, has the advantages of high overall strength and short construction time, and part of the structure can be recycled. Specifically, the enclosing structure for the foundation pit wall is formed through the cast-in-place piles, and the cast-in-place piles are connected into a whole through the crown beams and the waist beams, so that the overall strength of the enclosing structure is improved. The waist rail is filled to each bored concrete pile between through the pouring, has further improved the joint strength of waist rail and bored concrete pile, and horizontal bearing structure's application of force can avoid local bored concrete pile atress to concentrate and produce the damage on transmitting each bored concrete pile through the waist rail dispersion moreover. Each transverse supporting structure is formed by connecting a plurality of precast concrete supports, and the precast concrete supports, the precast concrete supports and the crown beam and the precast concrete supports and the waist beam are connected through connecting pieces respectively. And when the precast concrete support needs to be dismantled in the later stage, detaching the connecting piece between the precast concrete support and the waist beam, and chiseling the waist beam and the precast concrete support. When the length of the precast concrete support cannot be matched with the distance between the crown beams or the waist beams on the two sides, the total length of the transverse support structure can be controlled by adjusting the lengths of the connecting plates and the cast-in-place concrete sections.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:
fig. 1 is a schematic structural view of a supporting structure for a foundation pit of a subway station provided by the utility model;
FIG. 2 is a sectional view taken along line A-A in FIG. 1;
FIG. 3 is an enlarged view of portion B of FIG. 1;
FIG. 4 is an enlarged view of section C of FIG. 1;
FIG. 5 is an enlarged view of section D of FIG. 1;
FIG. 6 is an enlarged view of section E of FIG. 1;
in the figure, 100, filling piles; 200. a crown beam; 300. a wale; 400. a transverse support structure; 410. prefabricating a concrete support; 420. a connecting member; 421. a connecting plate; 422. a bolt group; 423. a nut; 424. a base; 500. a cast-in-place concrete section.
Detailed Description
In order to clearly explain the technical features of the present invention, the following detailed description of the present invention is provided with reference to the accompanying drawings.
It should be noted that in the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those described herein. Therefore, the scope of the utility model is not limited by the specific embodiments disclosed below.
As shown in fig. 1 and 2, the support structure for a subway station foundation pit provided by the present invention includes:
the enclosure structure is arranged close to the foundation pit wall and is formed by a plurality of filling piles 100 arranged at intervals;
a crown beam 200 horizontally connecting the tops of the cast-in-place piles 100;
a plurality of wales 300 horizontally connecting the pile bodies of the cast-in-place piles 100, wherein the wales 300 are formed by cast-in-place concrete, and the wales 300 are partially filled into gaps among the cast-in-place piles 100;
and a plurality of cross support structures 400 horizontally connected between the crown girders 200 and between the wales 300, wherein each cross support structure 400 is formed by connecting a plurality of precast concrete supports 410, and the precast concrete supports 410, the precast concrete supports 410 and the crown girders 200, and the precast concrete supports 410 and the wales 300 are respectively connected by connectors 420. The precast concrete support is assembled and connected with the crown beam and the waist beam after being transported to a construction site after being cast and molded in advance in a factory, so that the site construction time is shortened, and the precast concrete support can be recycled by disassembling the connecting piece after being used, so that the cost is saved.
The enclosure structure plays a role in retaining soil and prevents soil outside the foundation pit from collapsing. The crown beam 200 and the wale 300 connect the cast-in-place piles 100 into a whole, so that the overall strength of the enclosure structure is improved. Wale 300 fills to between each bored concrete pile 100 through the pouring, has further improved the joint strength of wale 300 with bored concrete pile 100, and the power of horizontal bearing structure can be transmitted to each bored concrete pile 100 through wale 300 dispersion moreover on, avoids local bored concrete pile 100 atress to concentrate and produces the damage.
The cross sections of the crown beam, the waist beam and the precast concrete support are square.
Specifically, as shown in fig. 3 to 5, each of the connection members 420 includes:
four connecting plates 421, each connecting plate 421 being provided with two groups of bolt holes, the connecting plates 421 being used to span between the precast concrete supports 410, between the precast concrete supports 410 and the crown beam 200, or between the precast concrete supports 410 and the wale 300;
and the bolt groups 422 are prefabricated around the end part of the precast concrete support 410, at the top of the crown beam 200 and at the top and the bottom of the wale 300, and the bolt groups 422 penetrate through bolt holes on the corresponding connecting plates 421 and then are fixedly connected with nuts 423.
For example, when connecting two precast concrete supports 410, after the ends of the two precast concrete supports 410 are butted, the two precast concrete supports 410 are connected by taking the connecting plate 421 and aligning the two sets of bolt holes on the connecting plate 421 with the bolt sets 422 on the two precast concrete supports 410 respectively, and then pressing down the connecting plate 421 to abut against the surface of the precast concrete supports 410, the bolt sets 422 pass through the bolt holes, and then fastening nuts 423 at the outer ends of the bolt sets 422.
When the precast concrete supports 410 and the wale 300 are connected, bolt groups 422 are fixed on a reinforcing steel frame of the wale 300, then connecting plates 421 are installed, so that the bolt groups 422 at the end parts of the precast concrete supports 410 are connected with the bolt groups 423 on the reinforcing steel frame of the wale 300 through the connecting plates 421, the four connecting plates 421 and supporting templates of the wale 300 jointly form a pouring cavity of the wale 300, and the connection of the wale 300 and the precast concrete supports 410 can be realized after the wale 300 reaches the solidification strength. And when the precast concrete supports 410 need to be removed at a later stage, the connecting pieces 420 between the precast concrete supports 410 and the wale 300 are detached, and the wale 300 and the precast concrete supports 410 are cut off.
In one embodiment, each bolt set 422 includes a base 424 and a plurality of bolts secured to the base 424. During prefabrication, the base is buried in the pouring cavity, and the end part of the bolt extends out of the pouring cavity.
As shown in fig. 4, a cast-in-place concrete section 500 is filled between the precast concrete support 410 and the crown sill 200 or the wale 300, the cast-in-place concrete section 500 is formed in a cavity surrounded by the connecting member 420, and the cast-in-place concrete section 500 is integrally formed with the wale 300. When the length of the precast concrete support 410 cannot be matched to the distance between the side wales, the control of the overall length can be achieved by adjusting the length of the connection plate and the cast-in-place concrete section 500.
Typically, the crown beam 200 is formed on top of each cast-in-place pile 100 by cast-in-place concrete.
Each layer of transverse supporting structure is generally supported on a soil layer below the foundation pit through lattice columns.
In the description of the present invention, it is to be understood that the terms "central," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," and the like are used in the indicated orientations and positional relationships based on the drawings for ease of description and simplicity of description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; the connection can be mechanical connection, electrical connection or communication; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.
The above-mentioned embodiments should not be construed as limiting the scope of the present invention, and any alternative modifications or alterations made to the embodiments of the present invention will fall within the scope of the present invention as those skilled in the art will appreciate.
The present invention is not described in detail, but is known to those skilled in the art.