CN112502165A - Reusable foundation pit PHC supporting member and construction method thereof - Google Patents
Reusable foundation pit PHC supporting member and construction method thereof Download PDFInfo
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- CN112502165A CN112502165A CN202011448324.3A CN202011448324A CN112502165A CN 112502165 A CN112502165 A CN 112502165A CN 202011448324 A CN202011448324 A CN 202011448324A CN 112502165 A CN112502165 A CN 112502165A
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
- E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
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Abstract
The invention discloses a reusable foundation pit PHC supporting member, which comprises PHC end prefabricated sections positioned at two ends and a PHC connection prefabricated section positioned between the two PHC end prefabricated sections; a first connecting structure extends from the end face of the outer end of the PHC end prefabricated section, and the first connecting structure is fixedly connected with a foundation pit supporting structure and poured to form a first post-pouring section; a second connecting structure extends from the end face of the inner end of the PHC end prefabricated section, a third connecting structure extends from the two end faces of the PHC end prefabricated section, and the second connecting structure and the third connecting structure are fixedly connected and poured to form a second post-pouring section; the first post-cast section and the second post-cast section are breakable, and the first connecting structure, the second connecting structure and the third connecting structure are severable. The reusable foundation pit PHC supporting member and the construction method thereof can meet engineering requirements, improve working efficiency, can be reused and reduce resource waste.
Description
Technical Field
The invention belongs to the technical field of civil engineering construction, and particularly relates to a reusable foundation pit PHC supporting member and a construction method thereof.
Background
Along with the continuous expansion of urban rail transit construction scale, long and narrow subway foundation pit engineering is more and more, and foundation pit width is unanimous basically. The construction of the foundation pit is limited by peripheral conditions, slope excavation can not be basically carried out, and a vertical type enclosure structure and an inner support are mostly adopted as a foundation pit supporting system.
The common inner support is provided with a reinforced concrete support and a steel pipe support, wherein the reinforced concrete support is mostly a rectangular straight support with an enlarged end. In the excavation process of the subway station foundation pit, the reinforced concrete support serving as a temporary support structure is quite common in a subway station open cut foundation pit enclosure support system due to the advantages of high support rigidity, good deformation control, strong compression and shear resistance, high safety and the like. However, the construction period of the main structure of the subway station is generally short, so the service life of the temporary support is usually not more than one year. In view of the self composition materials and characteristics of the reinforced concrete, the demolition process is long, the working efficiency is low, the labor intensity is high, the generated construction waste is easy to cause environmental pollution, and particularly, a large amount of dust, noise and the like generated in the demolition process are harmful to the health of field workers, so that the lives of surrounding residents are seriously influenced. The supporting system of the subway foundation pit, which can meet the engineering requirements, improve the working efficiency and reduce the resource waste, is urgently needed.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a reusable foundation pit PHC supporting member and a construction method thereof, which can meet engineering requirements, improve working efficiency, be reused and reduce resource waste.
The invention adopts the following technical scheme:
a reusable foundation pit PHC supporting member comprises PHC end prefabricated sections positioned at two ends and a PHC connection prefabricated section positioned between the two PHC end prefabricated sections;
a first connecting structure extends from the end face of the outer end of the PHC end prefabricated section, and the first connecting structure is fixedly connected with a foundation pit supporting structure and poured to form a first post-pouring section;
a second connecting structure extends from the end face of the inner end of the PHC end prefabricated section, third connecting structures extend from the two end faces of the PHC end prefabricated section, and the second connecting structure is fixedly connected with the third connecting structures and poured to form a second post-pouring section;
the first post-cast section and the second post-cast section are breakable, and the first connecting structure, the second connecting structure and the third connecting structure are severable.
As a further improvement of the technical scheme of the invention, the outer end of the prefabricated section at the end part of the PHC is provided with an enlarged head, the cross-sectional area of the enlarged head is gradually increased from inside to outside, and the first connecting structure is fixed on the end surface of the enlarged head.
As a further improvement of the technical scheme of the invention, the outer surfaces of the end parts of the PHC end prefabricated section and/or the PHC connection prefabricated section are fixedly coated with rigid shells, and the shape of each rigid shell is matched with the shape of the end part where the rigid shell is located.
As a further improvement of the technical scheme of the invention, the PHC end prefabricated section and/or the PHC connection prefabricated section are pre-tensioning prestressed prefabricated components.
As a further improvement of the technical scheme of the invention, the length of the second post-pouring section is not more than 2 times of the width of the section of the second post-pouring section.
As a further improvement of the technical scheme of the invention, both ends of the PHC end prefabricated section and/or the PHC connection prefabricated section are provided with hanging rings.
As a further improvement of the technical scheme of the invention, the first connecting structure is a first connection end plate, the first connection end plate is fixedly connected with a structural rib in the foundation pit supporting structure, and the connection between the first connection end plate and the structural rib can be cut off.
As a further improvement of the technical solution of the present invention, the second connecting structure is a second connection end plate, the third connecting structure is a third connection end plate, the second connection end plate and the third connection end plate are fixedly connected, and the connection between the second connection end plate and the third connection end plate can be cut off.
A construction method of the above-mentioned reusable foundation pit PHC supporting member, comprising the steps of:
manufacturing the PHC end prefabricated section and the PHC connection prefabricated section;
constructing a foundation pit supporting structure;
fixedly connecting the first connecting structures of the two PHC end prefabricated sections with foundation pit supporting structures on two sides respectively, and fixedly connecting the third connecting structure of the PHC connection prefabricated section with the second connecting structure;
pouring to form a first post-pouring section and a second post-pouring section;
and excavating a foundation pit and constructing a main body structure.
As a further improvement of the technical scheme of the invention, the method also comprises the following steps:
after the main structure is completed, the first post-pouring section and the second post-pouring section are destroyed, the third connecting structure and the second connecting structure are disassembled, the first connecting structure and the foundation pit supporting structure are disassembled, and the PHC end portion prefabricating section and the PHC connecting prefabricating section are recovered.
Compared with the prior art, the invention has the beneficial effects that:
according to the invention, the first post-cast section and the second post-cast section are destructible, the first connecting structure, the second connecting structure and the third connecting structure can be cut off, when the first post-cast section and the second post-cast section are dismounted, the PHC end prefabricated section and the PHC connection prefabricated section can be dismounted only by dismounting and destroying the first connecting structure, the second connecting structure and the third connecting structure, so that the PHC end prefabricated section and the PHC connection prefabricated section can be recycled for reuse. Through the arrangement, the use amount of the reinforced concrete of the supporting system is effectively reduced, the working efficiency of reinforced concrete supporting construction is improved, the labor intensity of operation workers is reduced, and the energy consumption and the environmental pollution are reduced.
Drawings
The technology of the present invention will be described in further detail with reference to the accompanying drawings and detailed description below:
FIG. 1 is a schematic diagram of the overall construction of a reusable foundation pit PHC support member of the present invention;
FIG. 2 is a top view of the reusable foundation pit PHC support member of the present invention;
fig. 3 is a plan view of the reusable foundation PHC support member of the present invention in a disassembled state.
Reference numerals:
100-PHC end prefabricated section; 110-a first connecting structure; 120-a second connecting structure; 130-an enlarged head;
200-PHC connecting the prefabricated sections; 210-a third connection structure;
300-a first post-cast section; 400-a second post-cast section;
500-a rigid housing; 600-a lifting ring; 700-foundation pit supporting construction; 710-supporting a foundation pit; 720-a crown beam; 730-structural ribs;
800-prestressed longitudinal steel bars; 810-hoop reinforcement.
Detailed Description
The conception, the specific structure and the technical effects of the present invention will be clearly and completely described in conjunction with the embodiments and the accompanying drawings to fully understand the objects, the schemes and the effects of the present invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The same reference numbers will be used throughout the drawings to refer to the same or like parts.
It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. Further, the description of the upper, lower, left, right, etc. used in the present invention is only with respect to the positional relationship of the respective components of the present invention with respect to each other in the drawings.
Example 1:
referring to fig. 1 to 3, a PHC supporting member for a reusable foundation pit includes PHC end precast sections 100 at both ends and a PHC connection precast section 200 between the two PHC end precast sections 100.
The PHC end prefabricated section 100 and the PHC connection prefabricated section 200 are both long strips and are both of a prestressed high-strength concrete structure, a plurality of prestressed longitudinal steel bars 800 and a plurality of hoop reinforcements 810 hooped on the prestressed longitudinal steel bars 800 are arranged in the PHC end prefabricated section 100 and the PHC connection prefabricated section 200, and the prestressed longitudinal steel bars 800 and the hoop reinforcements 810 are both embedded in the concrete structure. Specifically, the PHC end prefabricated section 100 and the PHC connection prefabricated section 200 are both pre-tensioning prestressed prefabricated components, and the applied prestress prevents the PHC end prefabricated section 100 and the PHC connection prefabricated section 200 from being damaged by tension fracture during installation, disassembly and hoisting.
A first connecting structure 110 extends from the end face of the outer end of the PHC end prefabricated section 100, and the first connecting structure 110 is fixedly connected with the foundation pit supporting structure 700 and poured to form a first post-pouring section 300. The first connecting structure 110 is connected with the foundation pit supporting structure 700 preliminarily, and then pouring is carried out, so that the strength of the connecting node is guaranteed, and safety is guaranteed. Here, the excavation supporting construction 700 may be a crown beam 720 at the upper end of the excavation supporting 710.
A second connecting structure 120 extends from the end surface of the inner end of the PHC end prefabricated section 100, third connecting structures 210 extend from the two end surfaces of the PHC connection prefabricated section 200, and the second connecting structure 120 and the third connecting structures 210 are fixedly connected and poured to form a second post-pouring section 400. Similarly, the PHC end prefabricated section 100 and the PHC connection prefabricated section 200 are connected and fixed through the second connection structure 120 and the third connection structure 210, and then pouring is performed, so as to ensure the strength of the connection node and ensure safety.
After the connection is completed, the first post-cast section 300, the second post-cast section 400, the PHC end prefabricated section 100 and the PHC connection prefabricated section 200 together form the PHC supporting member of the foundation pit, and the structure of the foundation pit is transversely supported.
In addition, the first post-cast section 300 and the second post-cast section 400 can be damaged, and the first connecting structure 110, the second connecting structure 120 and the third connecting structure 210 can be cut off, so that when the subsequent removal is needed, the PHC end prefabricated section 100 and the PHC connecting prefabricated section 200 can be respectively detached and recycled only by destroying and removing the first post-cast section 300 and the second post-cast section 400, cutting off the connection part between the first connecting structure 110 and the foundation pit supporting structure 700 and cutting off the connection part between the second connecting structure 120 and the third connecting structure 210, the detached concrete structure is reduced, the generation of dust is reduced, the subsequent use of the recycled PHC end prefabricated section 100 and the PHC connecting prefabricated section 200 can further save the using amount of reinforced concrete, the working efficiency of reinforced concrete supporting construction is improved, the labor intensity of operating workers is reduced, the energy consumption is reduced, And (5) environmental pollution.
Specifically, first connection structure 110 is first refutes and connects the end plate, for the steel material, first refute connect the end plate with structural reinforcement 730 welded fastening in the excavation supporting structure 700 can be that the two lug weld is in the same place, if length is not enough, also can be in the same place through reinforcing bar overlap joint welding, increases the bending resistance between the component and cuts the performance, first refute connect the end plate with the connection of structural reinforcement can cut off, can cut first refute and connect end plate and/or structural reinforcement 730 at the junction to make follow-up can dismantle the prefabricated section 100 of PHC tip when dismantling and get back, realize resource reuse's purpose.
Similarly, second connection structure 120 refutes the end plate for the second, third connection structure 210 refutes the end plate for the third, and the two is the steel material, the second refute the end plate with the third refutes and connects end plate welded fastening, can be both direct welding, if length is not enough, can increase the bending resistance between the component and cut the performance through reinforcing bar overlap joint welding together, the second refutes the end plate with the third refutes the connection of connecting the end plate and can cut off, can refute the end plate and/or the third and refute the end plate and cut at the junction with the second to make follow-up can connect prefabricated section 200 splits with PHC tip 100, PHC when dismantling and retrieve, realize resource reuse's purpose.
Preferably, the outer end of the PHC end prefabricated section 100 is provided with an enlarged head 130, the cross-sectional area of the enlarged head 130 is gradually increased from inside to outside, in order to enhance the rigidity of the interconnection and reduce the damage of the member caused by stress concentration, and the first connecting structure 110 is fixed on the end surface of the enlarged head 130.
Preferably, a rigid outer shell 500 is fixed on the outer surface of each of the end portions of the PHC end prefabricated section 100 and/or the PHC connection prefabricated section 200 in a wrapping manner, the shape of the rigid outer shell 500 is matched with the shape of the end portion where the rigid outer shell 500 is located, and by arranging the rigid outer shell 500, when the first post-casting section 300 and the second post-casting section 400 are disassembled, the rigid outer shell 500 can protect the end portions of the PHC end prefabricated section 100 and/or the PHC connection prefabricated section 200. The rigid shell 500 may be a steel casing, which not only strengthens the connection strength between the joints, but also avoids the damage to the joint quality of the end of the PHC end prefabricated section 100 and the PHC connection prefabricated section 200 caused by the dismantling of the first post-pouring section 300 and the second post-pouring section 400.
Wherein, the length of the second post-cast section 400 is not more than 2 times of the width of the section of the second post-cast section, so as to avoid overlong and reduce the connection strength of the second post-cast section.
For convenience in hoisting, both ends of the PHC end prefabricated section 100 and/or the PHC connection prefabricated section 200 are provided with hoisting rings 600, so that the PHC end prefabricated section 100 and/or the PHC connection prefabricated section 200 can be conveniently hoisted by hoisting equipment for installation, and the construction efficiency is improved.
Example 2
A method of constructing a reusable foundation pit PHC support member as in example 1, comprising the steps of:
firstly, according to the design requirement of the universal support of the long and narrow foundation pit support 710 system, the PHC end prefabricated section 100 and the PHC connection prefabricated section 200 are prepared and manufactured in advance in a factory.
Secondly, according to a normal construction sequence, constructing a foundation pit supporting structure 700, namely constructing a foundation pit support 710 and stressed steel bars, casting a foundation pit crown beam 720 in situ after the material strength of the foundation pit crown beam reaches a certain value, and reserving a structural bar 730 connecting the crown beam 720 and the PHC end prefabricated section 100 for subsequent connection and fixation with the first connecting structure 110.
Secondly, hoisting the PHC end prefabricated sections 100 and the PHC connection prefabricated sections 200 by adopting hoisting equipment, respectively welding and fixing the first connection structures 110 of the two PHC end prefabricated sections 100 and the structural ribs 730 of the foundation pit supporting structures 700 at two sides, and welding and fixing the third connection structures 210 of the PHC connection prefabricated sections 200 and the second connection structures 120 to form a stable connection structure;
then, a first post-cast section 300 and a second post-cast section 400 are formed by casting, so that the connection rigidity and the bending and shearing resistance of the interface are further enhanced, and the support design requirements are met;
and after the first post-pouring section 300 and the second post-pouring section 400 reach the design strength, excavating the soil body inside the foundation pit to the bottom of the foundation pit in a layering mode, and constructing the main structure.
After the internal main structure of the foundation pit is completed, a high-pressure water gun or a pneumatic pick is adopted, the concrete of the first post-pouring section 300 and the second post-pouring section 400 is firstly removed, the first post-pouring section 300 and the second post-pouring section 400 are damaged, then the third connecting structure 210 and the second connecting structure 120 are cut off and split by means of a cutting machine, the first connecting structure 110 and the foundation pit supporting structure 700 are split, and the PHC end prefabricated section 100 and the PHC connection prefabricated section 200 are recovered and are transported away for repeated use through hoisting equipment.
Other contents of the reusable foundation pit PHC supporting member and the construction method thereof are referred to in the prior art and are not described herein again.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, so that any modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention are within the scope of the technical solution of the present invention.
Claims (10)
1. The utility model provides a repeatedly usable's foundation ditch PHC supporting member which characterized in that: the device comprises PHC end prefabricated sections positioned at two ends and a PHC connection prefabricated section positioned between the two PHC end prefabricated sections;
a first connecting structure extends from the end face of the outer end of the PHC end prefabricated section, and the first connecting structure is fixedly connected with a foundation pit supporting structure and poured to form a first post-pouring section;
a second connecting structure extends from the end face of the inner end of the PHC end prefabricated section, third connecting structures extend from the two end faces of the PHC end prefabricated section, and the second connecting structure is fixedly connected with the third connecting structures and poured to form a second post-pouring section;
the first post-cast section and the second post-cast section are breakable, and the first connecting structure, the second connecting structure and the third connecting structure are severable.
2. The reusable foundation pit PHC support member of claim 1, wherein: the outer end of the prefabricated section of the PHC end is provided with an expanding head, the cross-sectional area of the expanding head is gradually increased from inside to outside, and the first connecting structure is fixed on the end face of the expanding head.
3. The reusable foundation pit PHC support member of claim 1, wherein: the outer surfaces of the end parts of the PHC end part prefabricated section and/or the PHC connection prefabricated section are fixedly coated with rigid shells, and the shapes of the rigid shells are matched with the shapes of the end parts where the rigid shells are located.
4. The reusable foundation pit PHC support member of claim 1, wherein: the PHC end prefabricated section and/or the PHC connection prefabricated section are pre-tensioning prestressed prefabricated components.
5. The reusable foundation pit PHC support member of claim 1, wherein: the length of the second post-pouring section is not more than 2 times of the width of the section of the second post-pouring section.
6. The reusable foundation pit PHC support member of claim 1, wherein: and both ends of the PHC end prefabricated section and/or the PHC connection prefabricated section are provided with hanging rings.
7. The reusable foundation pit PHC support member of claim 1, wherein: first connection structure is first refutes and connects the end plate, first refute connect the end plate with structural reinforcement fixed connection in the excavation supporting structure, first refute connect the end plate with the connection of structural reinforcement can cut off.
8. The reusable foundation pit PHC support member of claim 1, wherein: the second connection structure is the second connection end plate, the third connection structure is the third connection end plate, the second connection end plate with the third connection end plate fixed connection is refuted, the second connection end plate with the third connection of refuting the end plate can cut off.
9. A method of constructing a reusable foundation pit PHC support member as claimed in any one of claims 1 to 8, comprising the steps of:
manufacturing the PHC end prefabricated section and the PHC connection prefabricated section;
constructing a foundation pit supporting structure;
fixedly connecting the first connecting structures of the two PHC end prefabricated sections with foundation pit supporting structures on two sides respectively, and fixedly connecting the third connecting structure of the PHC connection prefabricated section with the second connecting structure;
pouring to form a first post-pouring section and a second post-pouring section;
and excavating a foundation pit and constructing a main body structure.
10. The method of constructing a reusable foundation pit PHC support member of claim 9, wherein: further comprising the steps of:
after the main structure is completed, the first post-pouring section and the second post-pouring section are destroyed, the third connecting structure and the second connecting structure are disassembled, the first connecting structure and the foundation pit supporting structure are disassembled, and the PHC end portion prefabricating section and the PHC connecting prefabricating section are recovered.
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CN202011448324.3A CN112502165A (en) | 2020-12-11 | 2020-12-11 | Reusable foundation pit PHC supporting member and construction method thereof |
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CN202011448324.3A CN112502165A (en) | 2020-12-11 | 2020-12-11 | Reusable foundation pit PHC supporting member and construction method thereof |
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Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104975605A (en) * | 2015-06-19 | 2015-10-14 | 刘鑫锦 | Technology for recyclable reinforced concrete support |
CN111395351A (en) * | 2020-02-25 | 2020-07-10 | 中铁第四勘察设计院集团有限公司 | Assembled supporting structure of foundation pit and supporting construction method |
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2020
- 2020-12-11 CN CN202011448324.3A patent/CN112502165A/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104975605A (en) * | 2015-06-19 | 2015-10-14 | 刘鑫锦 | Technology for recyclable reinforced concrete support |
CN111395351A (en) * | 2020-02-25 | 2020-07-10 | 中铁第四勘察设计院集团有限公司 | Assembled supporting structure of foundation pit and supporting construction method |
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