阅读说明：本技术 基坑围护结构及其施工方法 (Foundation pit support structure and construction method thereof ) 是由 张燕 于廷新 涂启柱 熊大生 薛峰 王忠华 储团结 黄俊杰 彭俊伟 沈峥 谢凡 于 2020-11-27 设计创作，主要内容包括：本申请公开了一种基坑围护结构,包括围护桩墙、锚杆和锚固桩,所述围护桩墙围护在所述基坑的周围,所述锚杆一端与所述围护桩墙连接,另一端锚固至基坑的周围土体中,所述锚固桩设置于所述基坑的周围土体中,所述锚固桩配置为与所述锚杆的两端之间连接,以对所述锚杆提供锚固力。本申请还公开了一种基坑围护结构的施工方法,在基坑周边环境受限,现有锚杆长度施工难以满足需求的情况下,通过所述锚固桩配置为与所述锚杆的两端之间连接,所述锚固桩对所述锚杆提供锚固力,从而可以缩短锚杆长度,使其满足基坑周边环境,并且能够有效提供锚固力,有效固定周围土体,防止基坑变形。(The application discloses foundation pit retaining structure, including enclosure pile wall, stock and anchor pile, enclosure pile wall encloses around the foundation pit, stock one end with enclosure pile wall connects, and the other end anchor is to in the surrounding soil body of foundation pit, the anchor pile set up in the surrounding soil body of foundation pit, the anchor pile configure into with connect between the both ends of stock, in order to right the stock provides the anchor power. The application also discloses a construction method of the foundation pit support structure, the foundation pit surrounding environment is limited, and the existing anchor rod length construction is difficult to meet the requirement, through the anchor pile configuration with be connected between the two ends of the anchor rod, the anchor pile is right the anchor rod provides the anchoring force, so that the anchor rod length can be shortened, the foundation pit surrounding environment can be met, the anchoring force can be effectively provided, the surrounding soil body can be effectively fixed, and the foundation pit is prevented from being deformed.)

1. A foundation pit support structure is characterized by comprising:

the enclosure pile wall is enclosed around the foundation pit;

one end of the anchor rod is connected with the enclosure pile wall, and the other end of the anchor rod is anchored in the surrounding soil body of the foundation pit; and

and the anchoring pile is arranged in the soil body around the foundation pit, and is configured to be connected with the two ends of the anchor rod so as to provide anchoring force for the anchor rod.

2. A building envelope according to claim 1, wherein the anchor piles comprise a first section and a second section connected, the second section comprising at least two bifurcated piles, the anchor rods being snapped between the two bifurcated piles.

3. A building envelope according to claim 2, wherein the first section of the anchor piles is polygonal in cross-section; and/or the cross section of the forked pile is polygonal.

4. A building envelope according to claim 2, characterized in that the end of the bifurcated pile has a cutting foot extending obliquely upwards from the outer side to the inner side of the end of the bifurcated pile.

5. A building envelope of claim 2, wherein the anchor rod comprises a free section, a transition section and an anchoring section which are connected in sequence, the free section is connected with the building envelope wall, the diameter of the anchoring section is larger than that of the free section, and the transition section is clamped between the two forked piles.

6. A building envelope according to claim 5, wherein the transition section has a diameter that gradually increases from the free section to the anchored section.

7. A building envelope according to claim 5, wherein the diameter of the anchored section is 1.2-4 times the diameter of the free section.

8. The enclosure structure of any one of claims 1 to 7, wherein the height of the anchor piles above the soil surrounding the foundation pit is greater than or equal to 0.5 m.

9. A building envelope of any one of claims 1 ~ 7, wherein, the anchor stake is prefabricated steel pile.

10. A building envelope of any one of claims 1 to 7, wherein the pile wall includes:

the fender post is arranged around the foundation pit; and

the beam body is connected with a plurality of the fender piles; one end of the anchor rod is connected with the fender pile or the beam body.

11. A construction method of a foundation pit support structure is characterized by comprising the following steps:

s1, constructing a retaining pile wall in the soil body around the foundation pit to be excavated;

s2, perforating the wall of the fender post, and applying anchor rods to the surrounding soil of the foundation pit;

s3, arranging anchoring piles in the soil around the foundation pit and clamping the anchoring piles with the two ends of the anchor rods;

and S4, downwards excavating the foundation pit to a preset depth, and constructing a foundation pit foundation structure.

12. The construction method according to claim 11, further comprising:

and S5, after the foundation pit foundation structure is finished, pulling out the anchoring pile, and backfilling the hole.

Technical Field

The application relates to the field of construction of constructional engineering, in particular to a foundation pit support structure and a construction method thereof.

Background

Along with the development of underground space technology, the deep foundation pit engineering of ultra-large area increases day by day, the large-scale comprehensive transportation hub engineering foundation pit area is as much as ten thousand flat, when the periphery is close to the existing structures and the stratum is poor, the foundation pit supporting difficulty is high, the foundation pit is deformed, the traditional pile support supporting cannot be integrally implemented due to the fact that the size area of the foundation pit is large, the partition excavation cost is high, the construction period is long, the anchoring section of a pile anchor system in the poor stratum is too long, and the safety of the close structure is influenced.

Disclosure of Invention

An object of the embodiment of the application is to provide a foundation pit support structure and a construction method thereof, so as to solve the problems that the construction environment is limited and the existing anchor rod is difficult to implement.

In order to solve the above problems, the present application is implemented by using the following technical solutions:

an aspect of the embodiment of the application provides a foundation ditch envelope, includes:

the enclosure pile wall is enclosed around the foundation pit;

one end of the anchor rod is connected with the enclosure pile wall, and the other end of the anchor rod is anchored in the surrounding soil body of the foundation pit; and

and the anchoring pile is arranged in the soil body around the foundation pit, and is configured to be connected with the two ends of the anchor rod so as to provide anchoring force for the anchor rod.

Further, anchor pile is including the first section and the second section of connection, the second section includes two at least forked piles, the stock joint is in two between the forked pile.

Further, the cross section of the first section of the anchoring pile is polygonal; and/or the cross section of the forked pile is polygonal.

Further, the end of the bifurcated pile is provided with a cutting foot which extends from the outer side face to the inner side face of the end of the bifurcated pile in an upward inclined mode.

Further, the stock is including the free section, changeover portion and the anchor section that connect gradually, the free section with the enclosure pile wall is connected, the diameter of anchor section is greater than the diameter of free section, the changeover portion joint is in two between the forked pile.

Further, the diameter of the transition section gradually increases from the free section to the anchoring section.

Further, the diameter of the anchoring section is 1.2-4 times of that of the free section.

Furthermore, the height of the anchoring pile higher than the soil body around the foundation pit is more than or equal to 0.5 m.

Further, the anchoring pile is a prefabricated steel pile.

Further, the enclosure pile wall includes:

the fender post is arranged around the foundation pit; and

the beam body is connected with a plurality of the fender piles; one end of the anchor rod is connected with the fender pile or the beam body.

In another aspect of the embodiment of the application, a construction method for a foundation pit support structure is provided, which includes:

s1, constructing a retaining pile wall in the soil body around the foundation pit to be excavated;

s2, perforating the wall of the fender post, and applying anchor rods to the surrounding soil of the foundation pit;

s3, arranging anchoring piles in the soil around the foundation pit and clamping the anchoring piles with the two ends of the anchor rods;

and S4, downwards excavating the foundation pit to a preset depth, and constructing a foundation pit foundation structure.

Further, the construction method further comprises the following steps:

and S5, after the foundation pit foundation structure is finished, pulling out the anchoring pile, and backfilling the hole.

The foundation pit enclosure structure comprises an enclosure pile wall, an anchor rod and an anchoring pile, wherein the enclosure pile wall is enclosed around a foundation pit, one end of the anchor rod is connected with the enclosure pile wall, and the other end of the anchor rod is anchored into a surrounding soil body of the foundation pit. Set up in the soil body around the foundation ditch through the anchor pile, the anchor pile configuration be for with be connected between the both ends of stock, the anchor pile provides anchor power to the stock, effectively fixes the soil body around, prevents that the foundation ditch from warping, protects the safety of structure around the foundation ditch. Especially, the foundation ditch all ring border is restricted, and under the condition that current stock length construction is difficult to satisfy the demand, through the linkage effect of anchor pile and stock to can shorten stock length, make it satisfy foundation ditch all ring border, can effectively provide the anchor power.

Drawings

Fig. 1 is a schematic view of a foundation pit support structure provided in an embodiment of the present application;

FIG. 2 is a top view of FIG. 1, with the surrounding soil of the foundation pit of FIG. 1 omitted to show the anchor rods;

fig. 3 is a schematic structural diagram of an anchor pile provided in an embodiment of the present application;

FIG. 4 is a cross-sectional view of the anchor pile of FIG. 3 taken in the direction D-D;

FIG. 5 is a cross-sectional view of the anchor pile of FIG. 3 taken in the direction E-E; and

fig. 6 is a schematic flow chart of a construction method of a foundation pit support structure according to the present application.

Description of reference numerals:

1-the surrounding soil body of a foundation pit, 2-a retaining pile wall, 3-a foundation pit foundation structure, 4-an anchor pile, 5-an anchor rod, 21-a retaining pile, 22-a crown beam, 41-a first section, 42-a second section, 43-a forked pile, 43A-a cutting edge, 43B-an outer side surface, 43C-an inner side surface, 51-a free section, 52-a transition section and 53-an anchor section.

Detailed Description

The following detailed description of embodiments of the present application refers to the accompanying drawings.

It should be noted that, in the present application, technical features in examples and embodiments may be combined with each other without conflict, and the detailed description in the specific embodiment should be understood as an explanation of the gist of the present application and should not be construed as an improper limitation to the present application.

In the description of the present application, reference to the terms "first/second" merely distinguishes similar objects and does not denote a particular order, but rather the terms "first/second" may, where permissible, be interchanged with a particular order or sequence so that embodiments of the application described herein may be practiced in other than the order shown or described herein.

It should be understood that the orientation or positional relationship is based on that shown in the drawings. These directional terms are merely for convenience in describing the present application and to simplify the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.

As shown in fig. 1 to fig. 2, a foundation pit enclosure structure provided by the embodiment of the present application includes an enclosure pile wall 2, an anchor rod 5, and an anchor pile 4. The enclosure pile wall 2 encloses the periphery of the foundation pit, one end of the anchor rod 5 is connected with the enclosure pile wall 2, the other end of the anchor rod is anchored in the surrounding soil body 1 of the foundation pit, the anchoring pile 4 is arranged in the surrounding soil body 1 of the foundation pit, and the anchoring pile 4 is configured to be connected with the two ends of the anchor rod 5 so as to provide anchoring force for the anchor rod 5.

Through being connected between the both ends of anchor pile 4 and stock 5, can provide anchor power to stock 5 to make anchor pile 4 and stock 5 atress simultaneously, effectively solve the foundation ditch and warp, when preventing the successive layer excavation of foundation ditch, the foundation ditch pile body moves toward the foundation ditch direction. For example, in a foundation pit project with a small excavation depth, particularly a deep foundation pit project with an excavation depth of less than or equal to 7m, when a supporting structure of the traditional enclosure pile wall 2 and the anchor rod 5 cannot be adopted due to the limited local peripheral environment, the anchor rod 5 is provided with an anchoring force through the connection between the anchoring pile 4 and the two ends of the anchor rod 5, the length of the anchor rod 5 can be shortened, the construction requirement of the peripheral environment is met, the foundation pit deformation is effectively controlled, and the stability of the foundation pit is maintained.

In one embodiment, the fender post wall 2 comprises a fender post 21 and a beam body, the fender post 21 is arranged around the foundation pit, and the beam body is connected with a plurality of fender posts 21. The beam body comprises a crown beam 22 connecting the tops of the plurality of fender posts 21 and a wale connecting the waists of the plurality of fender posts 21. The anchor rods 5 are connected at one end to the fender posts 21 or to the beam body, for example to the crown beam 22 or to the wale. Specifically, the fender pile 21 is a cast-in-place pile, the cast-in-place pile is arranged around the foundation pit, the fender pile wall 2 is integrally connected with the crown beam 22 and the waist beam through the fender pile 21, the anchor rod 5 is connected with any part of the fender pile wall 2, for example, the fender pile wall 2 is connected with the fender pile 21 or the beam body, the fender pile wall 2 can stably protect the surrounding soil body 1 of the foundation pit, and therefore the stability of the surrounding soil body is maintained during excavation of the foundation pit.

In a specific embodiment, a plurality of anchor rods 5 are arranged at intervals on the crown beam 22, one end of each of the anchor rods 5 passes through the corresponding through hole on the crown beam 22 and the anchor rods 5 are locked by the anchor heads, so that the connection between the anchor rods 5 and the crown beam 22 is realized.

In one embodiment, as shown in fig. 3, the anchor pile 4 comprises a first section 41 and a second section 42 connected, the second section 42 comprising at least two bifurcated piles 43, for example two or more. The anchor rod 5 is clamped between at least two forked piles 43. Specifically, the second section 42 that anchor pile 4 connects includes two branching piles 43, 5 joints of stock are between two branching piles 43, through two branching pile 43 joint stock 5, make anchor pile 4 firmly connect stock 5, can provide stable joint simultaneously, with the anchor power of strengthening stock 5, two branching piles 43 can provide bigger anchor power simultaneously, the soil body 1 is in the soft condition of pine around the foundation ditch, still can effectively protect the foundation ditch, maintain the stability of foundation ditch.

In one embodiment, as shown in fig. 3, the end of the bifurcated pile 43 has a cutting edge 43A, and the cutting edge 43A extends obliquely upward from an outer side surface 43B to an inner side surface 43C of the end of the bifurcated pile 43. By the aid of the blade feet 43A of the forked piles 43, the anchoring piles 4 can be quickly driven into the surrounding soil body 1 of the foundation pit during construction, construction efficiency is improved, and construction time is saved.

In one embodiment, as shown in fig. 4-5, the first section 41 of the anchor pile 4 has a polygonal cross-section, and the bifurcated pile 43 has a polygonal cross-section. Specifically, the section of the first section 41 of the anchor pile 4 is rectangular or square, the section of the forked pile 43 is square or rectangular, the first section 41 and the forked pile 43 can adopt hot-rolled Q295 section steel or Q345 section steel, the square section is convenient for the anchor pile 4 to directly adopt the section steel to realize the function of the branched pile, the steps and processes of adopting other materials through various welding or other splicing forms are reduced, and the requirement of the foundation pit on the anchoring force of the anchor rod 5 can be met. It will be appreciated that the cross-section of the first section 41 of the anchor pile 4 and the bifurcated pile 43 may also be circular or oval, respectively.

In one embodiment, the anchor piles 4 are prefabricated steel piles. The prefabricated steel piles are adopted, so that the temporary construction of the steel piles on site is avoided, the construction operation efficiency of the enclosure structure is effectively improved, and the construction period is shortened.

In one embodiment, the height of the anchor pile 4 higher than the surrounding soil body 1 of the foundation pit is more than or equal to 0.5m, so that the anchor pile 4 can be conveniently pulled out from the surrounding soil body 1 of the foundation pit after the construction of the anchor pile 4 is completed, and the anchor pile 4 can be recycled.

In one embodiment, the anchor rod 5 comprises a free section 51, a transition section 52 and an anchoring section 53 which are connected in sequence, the free section 51 is connected with the enclosure pile wall 2, the diameter of the anchoring section 53 is larger than that of the free section 51, and the transition section 52 is clamped between the two forked piles 43. The diameter through anchor section 53 is greater than the diameter of free segment 51, and changeover portion 52 joint is between two forked piles 43 for changeover portion 52 can firmly joint between two forked piles 43, is difficult to deviate from, thereby makes anchor pile 4 firmly fix stock 5, prevents because the deformation that the foundation ditch continues to excavate and leads to. It will be appreciated that the distance between the two bifurcated piles 43 is greater than the outer diameter of the free section 51 and less than the outer diameter of the anchor section 53.

In one embodiment, the transition section 52 has a diameter that gradually increases from the free section 51 to the anchored section 53. Specifically, the transition section 52 is a circular truncated cone with a gradually changing diameter or a stepped circular truncated cone with a plurality of different diameters. The diameter through changeover portion 52 increases gradually from free segment 51 to anchor section 53 for during the construction of stock 5 joint changeover portion 52, even there is the deviation in the work progress, anchor pile 4 still can firmly, accurately joint changeover portion 52 of stock 5, in order to provide the anchor power, thereby make the construction operation nimble more simple and convenient, can also ensure envelope's stability and fastness.

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 80-150 mm, the diameter of the anchoring section 53 is 96-600 mm, and corresponding selection is performed according to the actual environment of the surrounding soil body 1 of the foundation pit, so that the design requirements are met, and the anchoring pile 4 is stably and firmly connected with the anchor rod 5 on the premise of effectively saving materials.

In another aspect of the embodiment of the application, as shown in fig. 6, a method for constructing a foundation pit support structure is provided, which includes:

s1, constructing a retaining pile wall in the soil around the foundation pit to be excavated;

s2, perforating the wall of the fender post, and applying anchor rods to the surrounding soil of the foundation pit;

s3, arranging anchoring piles in the soil around the foundation pit and clamping the anchoring piles with the two ends of the anchor rod;

and S4, downwards excavating the foundation pit to a preset depth, and constructing a foundation pit foundation structure.

By the construction method of the foundation pit enclosure structure, the foundation pit enclosure structure can complete the construction operation of the foundation pit under the condition that the length of the anchor rod in the existing enclosure structure is difficult to meet the anchoring requirement, so that the application range of the foundation pit enclosure structure is wider.

The following describes, in combination with fig. 1 to 5 and the foundation pit support structure according to any one of the embodiments, each step of the construction of the foundation pit support structure according to the embodiment of the present application.

S1, constructing a retaining pile wall in the soil around the foundation pit to be excavated.

Specifically, the retaining piles 21 are constructed in the surrounding soil body 1 of the foundation pit, for example, the retaining piles 21 are constructed by adopting a pouring method, the crown beams 22 connecting the tops of the plurality of retaining piles 21 are constructed, and the retaining piles 21 and the crown beams 22 form the retaining pile wall 2, so that the important support of the foundation pit retaining structure is realized. It can be understood that, in the process of excavation of the foundation pit layer by layer, a waist beam connecting the middle parts of the plurality of fender piles 21 can be further constructed, and the fender piles 21, the crown beams 22 and the waist beam form the fender pile wall 2 together.

And S2, perforating the wall of the fender post, and constructing anchor rods in the surrounding soil body of the foundation pit.

Specifically, when the strength of the enclosure pile wall 2 satisfies the design strength, a hole is drilled in the enclosure pile wall 2, for example, the enclosure pile 21, the crown beam 22 or the waist beam, a hole is opened in the surrounding soil body 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, so that the enclosure pile wall 2 is anchored.

And S3, arranging anchoring piles in the soil around the foundation pit, and clamping the anchoring piles with the two ends of the anchor rod.

Specifically, in the soil body 1 around the foundation pit, the anchor piles 4 are arranged, so that the bifurcated piles 43 of the anchor piles 4 are clamped with the transition sections 52 of the anchor rods 5, and the anchoring effect of the anchor rods 5 on the enclosure pile wall 2 is further strengthened. The anchor piles 4 can be prefabricated steel piles, for example, hot rolled Q295 and Q345 steel.

And S4, downwards excavating the foundation pit to a preset depth, and constructing a foundation pit foundation structure.

Specifically, the foundation pit is further excavated to a set depth, and the foundation pit foundation structure 3 is constructed, so that the enclosure structure required by the foundation pit is completed.

In an embodiment, the construction method of the foundation pit enclosure further includes:

and S5, after the foundation pit foundation structure is finished, pulling out the anchor pile, and backfilling the hole.

Specifically, after the foundation pit foundation structure 3 is constructed, the anchor piles 4 are pulled out, the holes are backfilled, the anchor piles 4 can be recycled, the construction cost is saved, the stability of the surrounding soil body of the foundation pit can be guaranteed by the backfilling holes, and the soil body cannot be damaged due to the constructed holes, so that the foundation pit enclosure structure is effectively protected.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions as claimed herein.