Foundation pit retaining structure and its construction method

Abstract

The present application discloses a foundation pit retaining structure, including a retaining pile wall, an anchor rod and an anchor pile, wherein the retaining pile wall surrounds the foundation pit, one end of the anchor rod is connected to the retaining pile wall, and the other end is anchored to the surrounding soil of the foundation pit, and the anchor pile is arranged in the surrounding soil of the foundation pit, and the anchor pile is configured to be connected between the two ends of the anchor rod to provide an anchoring force to the anchor rod. The present application also discloses a construction method for a foundation pit retaining structure, in the case where the surrounding environment of the foundation pit is limited and the existing anchor rod length construction is difficult to meet the demand, the anchor pile is configured to be connected between the two ends of the anchor rod, and the anchor pile provides an anchoring force to the anchor rod, thereby shortening the length of the anchor rod to meet the surrounding environment of the foundation pit, and can effectively provide an anchoring force, effectively fix the surrounding soil, and prevent the foundation pit from deforming.

Description

Technical Field

[0001] The present application relates to the field of building engineering construction, and in particular, to a foundation pit retaining structure and a construction method thereof. Background Art

[0002] With the development of underground space technology, ultra-large-scale deep foundation pit projects are increasing. The foundation pit area of ​​large-scale integrated transportation hub projects can reach hundreds of thousands of square meters. When there are existing structures nearby and the strata are poor, the foundation pit support is difficult and the foundation pit is deformed. Traditional pile support cannot be implemented as a whole due to the large size and area of ​​the foundation pit. The cost of zoning excavation is high and the construction period is long. The anchoring section of the pile-anchor system in poor strata is too long, affecting the safety of nearby structures. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a foundation pit retaining structure and a construction method thereof, so as to solve the problem that the construction environment is limited and the existing anchor rods are difficult to implement.

[0004] In order to solve the above problems, the present application adopts the following technical solutions:

[0005] In one aspect of an embodiment of the present application, a foundation pit retaining structure is provided, comprising:

[0006] A retaining pile wall, surrounding the foundation pit;

[0007] An anchor rod, one end of which is connected to the retaining pile wall, and the other end of which is anchored in the surrounding soil of the foundation pit; and

[0008] Anchor piles are arranged in the surrounding soil of the foundation pit, and the anchor piles are configured to be connected between the two ends of the anchor rod to provide anchoring force for the anchor rod.

[0009] Furthermore, the anchor pile comprises a first section and a second section which are connected, the second section comprises at least two bifurcated piles, and the anchor rod is clamped between the two bifurcated piles.

[0010] Furthermore, the cross-section of the first section of the anchor pile is a polygon; and / or the cross-section of the bifurcated pile is a polygon.

[0011] Furthermore, the end of the bifurcated pile has a blade foot, and the blade foot extends obliquely upward from the outer side surface of the end of the bifurcated pile to the inner side surface.

[0012] Furthermore, the anchor rod comprises a free section, a transition section and an anchoring section which are connected in sequence, the free section is connected to the retaining pile wall, the diameter of the anchoring section is larger than the diameter of the free section, and the transition section is clamped between the two bifurcated piles.

[0013] Furthermore, the diameter of the transition section gradually increases from the free section to the anchoring section.

[0014] Furthermore, the diameter of the anchoring section is 1.2 to 4 times the diameter of the free section.

[0015] Furthermore, the height of the anchor piles above the surrounding soil of the foundation pit is ≥0.5m.

[0016] Furthermore, the anchor piles are prefabricated steel piles.

[0017] Furthermore, the retaining pile wall comprises:

[0018] Retaining piles are arranged around the foundation pit; and

[0019] The beam body is connected with a plurality of the retaining piles; one end of the anchor rod is connected with the retaining pile or the beam body.

[0020] In another aspect of the embodiment of the present application, a construction method of a foundation pit retaining structure is provided, comprising:

[0021] S1. constructing a retaining pile wall in the surrounding soil of the foundation pit to be excavated;

[0022] S2, drilling holes in the retaining pile wall and placing anchor rods in the surrounding soil of the foundation pit;

[0023] S3, setting anchor piles in the surrounding soil of the foundation pit and clamping between the two ends of the anchor rod;

[0024] S4. Dig the foundation pit downward to a preset depth and construct the foundation pit foundation structure.

[0025] Furthermore, the construction method also includes:

[0026] S5. After the foundation pit foundation structure is completed, pull out the anchor piles and backfill the pores.

[0027] The embodiment of the present application provides a foundation pit retaining structure and a construction method thereof, wherein the foundation pit retaining structure includes a retaining pile wall, an anchor rod and an anchor pile, wherein the retaining pile wall surrounds the foundation pit, one end of the anchor rod is connected to the retaining pile wall, and the other end is anchored to the surrounding soil of the foundation pit. The anchor pile is set in the surrounding soil of the foundation pit, and the anchor pile is configured to be connected to the two ends of the anchor rod. The anchor pile provides an anchoring force to the anchor rod, effectively fixes the surrounding soil, prevents the foundation pit from deforming, and protects the safety of the structure around the foundation pit. In particular, when the surrounding environment of the foundation pit is limited and the existing anchor rod length construction is difficult to meet the demand, the connection between the anchor pile and the anchor rod can shorten the length of the anchor rod so that it meets the surrounding environment of the foundation pit and can effectively provide an anchoring force. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a foundation pit retaining structure provided in an embodiment of the present application;

[0029] Figure 2 for Figure 1 Top view of the anchor bolt is omitted to show the anchor bolt. Figure 1 The surrounding soil of the medium foundation pit;

[0030] Figure 3 A schematic diagram of the structure of an anchor pile provided in an embodiment of the present application;

[0031] Figure 4 for Figure 3 Cross-section of the anchor pile in the mid-DD direction;

[0032] Figure 5 for Figure 3 Cross-section of the anchor pile in the mid-EE direction; and

[0033] Figure 6 A schematic flow chart of a construction method of a foundation pit retaining structure provided for the implementation of this application.

[0034] Description of reference numerals:

[0035] 1-soil around foundation pit, 2-retaining pile wall, 3-foundation pit foundation structure, 4-anchor pile, 5-anchor rod, 21-retaining pile, 22-crown beam, 41-first section, 42-second section, 43-forked pile, 43A-blade foot, 43B-outer side, 43C-inner side, 51-free section, 52-transition section, 53-anchor section. DETAILED DESCRIPTION

[0036] The specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0037] It should be noted that, in the absence of conflict, the embodiments and technical features in the embodiments of the present application can be combined with each other, and the detailed description in the specific implementation method should be understood as an explanation of the purpose of the present application and should not be regarded as an improper limitation on the present application.

[0038] In the description of the present application, the terms "first / second" involved are merely used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first / second" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0039] It should be understood that the orientation or position relationship is based on the orientation or position relationship shown in the drawings. These orientation terms are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0040] like Figure 1-2 As shown, a foundation pit retaining structure proposed in an embodiment of the present application includes a retaining pile wall 2, an anchor rod 5 and an anchor pile 4. The retaining pile wall 2 surrounds the foundation pit, one end of the anchor rod 5 is connected to the retaining pile wall 2, and the other end is anchored to the surrounding soil 1 of the foundation pit, and the anchor pile 4 is arranged in the surrounding soil 1 of the foundation pit, and the anchor pile 4 is configured to be connected between the two ends of the anchor rod 5 to provide an anchoring force to the anchor rod 5.

[0041] By connecting the anchor pile 4 with the two ends of the anchor rod 5, an anchoring force can be provided to the anchor rod 5, so that the anchor pile 4 and the anchor rod 5 are stressed at the same time, effectively solving the deformation of the foundation pit and preventing the foundation pit pile body from moving toward the foundation pit when the foundation pit is excavated layer by layer. For example, in a foundation pit project with a small excavation depth, especially a deep foundation pit project with an excavation depth of ≤7m, due to the limited local surrounding environment, when the support structure of the traditional retaining pile wall 2 and the anchor rod 5 cannot be used, the anchor pile 4 is connected with the two ends of the anchor rod 5 to provide an anchoring force to the anchor rod 5, and the length of the anchor rod 5 can be shortened to meet the construction requirements of the surrounding environment, thereby effectively controlling the deformation of the foundation pit and maintaining the stability of the foundation pit.

[0042] In one embodiment, the retaining pile wall 2 includes retaining piles 21 and a beam body, wherein the retaining piles 21 are arranged around the foundation pit, and the beam body connects a plurality of retaining piles 21. The beam body includes a crown beam 22 connecting the tops of a plurality of retaining piles 21 and a waist beam connecting the waists of a plurality of retaining piles 21. One end of the anchor rod 5 is connected to the retaining piles 21 or to the beam body, for example, to the crown beam 22 or to the waist beam. Specifically, the retaining piles 21 are cast-in-place piles, which are arranged around the foundation pit, and the retaining pile wall 2 is formed as a whole by connecting the retaining piles 21 with the crown beam 22 and the waist beam. The anchor rod 5 is connected to any part of the retaining pile wall 2, for example, to the retaining piles 21 or the beam body, so that the retaining pile wall 2 can stably retain the surrounding soil 1 of the foundation pit, thereby maintaining the stability of the surrounding soil during the excavation of the foundation pit.

[0043] In a specific embodiment, a plurality of anchor rod 5 penetration holes are arranged at intervals on the crown beam 22 , one end of the plurality of anchor rods 5 passes through the corresponding penetration holes on the crown beam 22 respectively and the anchor rods 5 are locked with anchor heads, thereby achieving connection between the anchor rods 5 and the crown beam 22 .

[0044] In one embodiment, if Figure 3As shown, the anchor pile 4 includes a first section 41 and a second section 42 connected, and the second section 42 includes at least two bifurcated piles 43, for example, two or more. The anchor rod 5 is clamped between the at least two bifurcated piles 43. Specifically, the second section 42 connected by the anchor pile 4 includes two bifurcated piles 43, and the anchor rod 5 is clamped between the two bifurcated piles 43. The anchor rod 5 is clamped by the two bifurcated piles 43, so that the anchor pile 4 is firmly connected to the anchor rod 5, and at the same time, a stable clamping can be provided to strengthen the anchoring force of the anchor rod 5. At the same time, the two bifurcated piles 43 can provide a greater anchoring force. When the soil 1 around the foundation pit is in a relatively soft state, the foundation pit can still be effectively protected and the stability of the foundation pit can be maintained.

[0045] In one embodiment, if Figure 3 As shown, the end of the bifurcated pile 43 has a blade foot 43A, and the blade foot 43A extends upward from the outer side surface 43B of the end of the bifurcated pile 43 to the inner side surface 43C. Through the blade foot 43A of the bifurcated pile 43, the anchor pile 4 can be quickly driven into the surrounding soil 1 of the foundation pit during construction, thereby improving construction efficiency and saving construction time.

[0046] In one embodiment, if Figures 4-5 As shown, the cross section of the first section 41 of the anchor pile 4 is a polygon, and the cross section of the bifurcated pile 43 is a polygon. Specifically, the cross section of the first section 41 of the anchor pile 4 is a rectangle or a square, and the cross section of the bifurcated pile 43 is a square or a rectangle. The first section 41 and the bifurcated pile 43 can be made of hot-rolled Q295 steel or Q345 steel. The square cross section facilitates the anchor pile 4 to directly use steel to achieve the role of a branch pile, reducing the steps and processes of using other materials through multiple welding or other splicing forms, and at the same time can meet the anchoring force requirements of the foundation pit for the anchor rod 5. It can be understood that the cross sections of the first section 41 of the anchor pile 4 and the bifurcated pile 43 can also be circular or elliptical, respectively.

[0047] In one embodiment, the anchor piles 4 are prefabricated steel piles. The use of prefabricated steel piles avoids the need for temporary construction of steel piles on site, effectively improves the construction efficiency of the enclosure structure, and reduces the construction period.

[0048] In one embodiment, the height of the anchor pile 4 above the surrounding soil 1 of the foundation pit is ≥0.5m, so that after the construction of the anchor pile 4 is completed, the anchor pile 4 can be easily pulled out from the surrounding soil 1 of the foundation pit, and the anchor pile 4 can be recycled.

[0049] In one embodiment, the anchor rod 5 includes a free section 51, a transition section 52 and an anchor section 53 connected in sequence, the free section 51 is connected to the retaining pile wall 2, the diameter of the anchor section 53 is larger than the diameter of the free section 51, and the transition section 52 is clamped between the two bifurcated piles 43. Since the diameter of the anchor section 53 is larger than the diameter of the free section 51, the transition section 52 is clamped between the two bifurcated piles 43, so that the transition section 52 can be firmly clamped between the two bifurcated piles 43 and is not easy to come out, so that the anchor pile 4 firmly fixes the anchor rod 5 to prevent deformation caused by continued excavation of the foundation pit. It can be understood that the distance between the two bifurcated piles 43 is greater than the outer diameter of the free section 51 and smaller than the outer diameter of the anchor section 53.

[0050] In one embodiment, the diameter of the transition section 52 gradually increases from the free section 51 to the anchoring section 53. Specifically, the transition section 52 is a truncated cone with a gradually changing diameter or a stepped truncated cone with multiple different diameters. The diameter of the transition section 52 gradually increases from the free section 51 to the anchoring section 53, so that when the anchor rod 5 is clamped to the transition section 52, even if there is a deviation during the construction process, the anchor pile 4 can still firmly and accurately clamp the transition section 52 of the anchor rod 5 to provide anchoring force, thereby making the construction operation more flexible and simple, and ensuring the stability and firmness of the enclosure structure.

[0051] In one embodiment, the diameter of the anchoring section 53 is 1.2 to 4 times the diameter of the free section 51. Specifically, the diameter of the free section 51 is 80 to 150 mm, and the diameter of the anchoring section 53 is 96 to 600 mm. According to the actual surrounding soil 1 environment of the foundation pit, a corresponding selection is made to meet the design requirements, and the anchor pile 4 is stably and firmly connected to the anchor rod 5 under the premise of effectively saving materials.

[0052] Another aspect of the embodiment of the present application is as follows Figure 6 As shown, a construction method of a foundation pit retaining structure is provided, comprising:

[0053] S1. Construct retaining pile walls in the surrounding soil of the foundation pit to be excavated;

[0054] S2. Drill holes in the retaining pile wall and install anchor rods in the surrounding soil of the foundation pit;

[0055] S3, setting anchor piles in the surrounding soil of the foundation pit and clamping the two ends of the anchor rod;

[0056] S4. Dig the foundation pit downwards to the preset depth and construct the foundation pit foundation structure.

[0057] Through the construction method of the foundation pit retaining structure, the foundation pit retaining structure can complete the construction work of the foundation pit when the anchor rod length in the existing retaining structure is difficult to meet the anchoring requirements, thereby making its application range wider.

[0058] Combine the following Figures 1 to 5 As well as the foundation pit retaining structure of any of the above-mentioned embodiments, each step of the construction of the foundation pit retaining structure of the embodiment of the present application is specifically described.

[0059] S1. Construct retaining pile walls in the surrounding soil of the foundation pit to be excavated.

[0060] Specifically, retaining piles 21 are constructed in the surrounding soil 1 of the foundation pit, for example, the retaining piles 21 are constructed by the pouring method, and a crown beam 22 is constructed to connect the tops of multiple retaining piles 21. The retaining piles 21 and the crown beam 22 form a retaining pile wall 2, thereby achieving important support for the foundation pit retaining structure. It is understandable that during the excavation of the foundation pit layer by layer, a waist beam connecting the middle parts of multiple retaining piles 21 can also be constructed, and the retaining piles 21, the crown beam 22 and the waist beam together form a retaining pile wall 2.

[0061] S2. Drill holes in the retaining pile wall and install anchor rods in the surrounding soil of the foundation pit.

[0062] Specifically, when the strength of the retaining pile wall 2 meets the design strength, holes are drilled on the retaining pile wall 2, for example, holes are drilled on the retaining piles 21, the crown beam 22 or the waist beam, holes are opened in the surrounding soil 1 of the foundation pit, and the anchoring section 53, the transition section 52 and the free section 51 of the anchor rod 5 are constructed, thereby anchoring the retaining pile wall 2.

[0063] S3. Anchor piles are set in the surrounding soil of the foundation pit to clamp the two ends of the anchor rods.

[0064] Specifically, anchor piles 4 are driven into the soil 1 around the foundation pit, so that the bifurcated piles 43 of the anchor piles 4 are engaged with the transition section 52 of the anchor rod 5, thereby further strengthening the anchoring effect of the anchor rod 5 on the retaining pile wall 2. The anchor piles 4 can be prefabricated steel piles, for example, hot-rolled Q295 or Q345 steel.

[0065] S4. Dig the foundation pit downwards to the preset depth and construct the foundation pit foundation structure.

[0066] Specifically, the foundation pit is further excavated to a set depth, and the foundation pit foundation structure 3 is constructed, thereby completing the retaining structure required for the foundation pit.

[0067] In one embodiment, the construction method of the foundation pit retaining structure further includes:

[0068] S5. After the foundation pit structure is completed, pull out the anchor piles and backfill the pores.

[0069] Specifically, after the construction of the foundation pit foundation structure 3 is completed, the anchor piles 4 can be recovered by pulling out the anchor piles 4 and backfilling the pores, and can be recycled for multiple times, saving construction costs. At the same time, backfilling the pores can ensure the stability of the soil around the foundation pit, and will not cause soil damage due to the constructed pores, thereby effectively protecting the foundation pit retaining structure.

[0070] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the same. Although the present application has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present application.

Claims

1. A foundation pit retaining structure, characterized in that: include: A retaining pile wall, surrounding the foundation pit; An anchor rod, one end of which is connected to the retaining pile wall, and the other end of which is anchored in the surrounding soil of the foundation pit; as well as Anchor piles are arranged in the soil around the foundation pit, and the anchor piles are configured to be connected between the two ends of the anchor rod to provide anchoring force for the anchor rod; The anchor pile comprises a first section and a second section that are connected, the second section comprises at least two bifurcated piles, and the anchor rod is clamped between the two bifurcated piles.

2. The enclosure structure according to claim 1, characterized in that: The cross section of the first section of the anchor pile is a polygon; and / or the cross section of the bifurcated pile is a polygon.

3. The enclosure structure according to claim 1, characterized in that: The end of the bifurcated pile has a blade foot, and the blade foot extends obliquely upward from the outer side surface of the end of the bifurcated pile to the inner side surface.

4. The enclosure structure according to claim 1, characterized in that: The anchor rod comprises a free section, a transition section and an anchoring section which are connected in sequence. The free section is connected to the retaining pile wall. The diameter of the anchoring section is larger than that of the free section. The transition section is clamped between the two bifurcated piles.

5. The enclosure structure according to claim 4, characterized in that: The diameter of the transition section gradually increases from the free section to the anchoring section.

6. The enclosure structure according to claim 4, characterized in that: The diameter of the anchoring section is 1.2 to 4 times the diameter of the free section.

7. The enclosure structure according to any one of claims 1 to 6, characterized in that: The height of the anchor piles above the surrounding soil of the foundation pit is ≥0.5m.

8. The enclosure structure according to any one of claims 1 to 6, characterized in that: The anchor piles are prefabricated steel piles.

9. The enclosure structure according to any one of claims 1 to 6, characterized in that: The retaining pile wall comprises: Retaining piles are arranged around the foundation pit; and The beam body is connected with a plurality of the retaining piles; one end of the anchor rod is connected with the retaining pile or the beam body.

10. A construction method for a foundation pit retaining structure, characterized in that: Applied to the enclosure structure according to any one of claims 1 to 9, the construction method comprises: S1. constructing a retaining pile wall in the surrounding soil of the foundation pit to be excavated; S2, drilling holes in the retaining pile wall and placing anchor rods in the surrounding soil of the foundation pit; S3, setting anchor piles in the surrounding soil of the foundation pit and clamping between the two ends of the anchor rod; S4. Dig the foundation pit downward to a preset depth and construct the foundation pit foundation structure.

11. The construction method according to claim 10, characterized in that: Also includes: S5. After the foundation pit foundation structure is completed, pull out the anchor piles and backfill the pores.

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