Pile anchor support deep foundation pit combined supporting structure

Abstract

The utility model belongs to the technical field of foundation pit supporting, and particularly discloses a pile anchor supporting deep foundation pit combined supporting structure which comprises a plurality of secant piles, a plurality of high-pressure jet grouting piles, a foundation pit crown beam, a plurality of enclosing purlins, a plurality of inner supporting layers and a plurality of foundation pit anchor cables. The high-pressure jet grouting piles are used for being sequentially arranged on the side edge of a foundation pit in a surrounding mode, located on the outer side of the inner ring enclosure and in contact with the outer side of the inner ring enclosure to form an outer ring enclosure, the foundation pit top beam is fixed to the secant piles and used for stretching across the top of the foundation pit, the surrounding purlins are arranged on the secant piles at intervals from top to bottom, and the inner supporting layers are arranged on the surrounding purlins in a one-to-one correspondence mode. The multiple foundation pit anchor cables are used for being buried in the side edge of a foundation pit and connected with the surrounding purlins located on the lower portions of the secant piles. The utility model is suitable for various complicated geological and hydrological conditions, and provides a safer solution for the construction of the deep foundation pit.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of foundation pit support, especially relates to a pile anchor support deep foundation pit combined support structure. BACKGROUND

[0002] With the acceleration of urbanization, deep foundation pit engineering appears more and more in underground building, subway construction and other large infrastructure engineering.

[0003] Deep foundation pit excavation often faces technical problems such as soft soil, high underground water level and difficult guarantee of support stability. Although the traditional foundation pit support mode such as soil nailing wall and steel sheet pile is effective in some occasions, its stability and water stopping effect are not ideal under high water level or soft soil layer, and problems such as support instability or water leakage may occur.

[0004] Therefore, how to ensure the safe excavation of deep foundation pit under complex soil layer and high water level environment and provide a stable and reliable support system has become an important issue in construction design. UTILITY MODEL CONTENTS

[0005] In view of the above problems, the utility model aims at providing a pile anchor support deep foundation pit combined support structure, which provides a safer solution for deep foundation pit construction.

[0006] The technical scheme of the utility model is: a pile anchor support deep foundation pit combined support structure, comprising:

[0007] A plurality of interlocking piles are used to be sequentially arranged on the side of the foundation pit to form an inner ring enclosure.

[0008] A plurality of high-pressure rotary jet piles are used to be sequentially arranged on the side of the foundation pit, located outside the inner ring enclosure and in contact with the outer side of the inner ring enclosure, to form an outer ring enclosure.

[0009] A foundation pit corbel is fixed on the interlocking pile and used to span the top of the foundation pit.

[0010] A plurality of surrounding purlins are arranged on the interlocking pile from top to bottom.

[0011] A plurality of inner support layers are arranged on the surrounding purlins one by one and used to support the inner ring enclosure.

[0012] A plurality of foundation pit anchor cables are used to be buried in the side of the foundation pit and connected with the surrounding purlin located at the lower part of the interlocking pile.

[0013] Further, the longitudinal section of the foundation pit corbel is a rectangular structure, and the size of the rectangular structure of the longitudinal section of the foundation pit corbel is 1100mm-1300mm*7mm-8mm.

[0014] Further, the surrounding purlin comprises:

[0015] The first surrounding purlin is at least two, and is arranged on the upper part of the bite pile in a spaced manner from top to bottom.

[0016] The second surrounding purlin is at least one, and is arranged on the lower part of the bite pile.

[0017] Further, the longitudinal section of the first surrounding purlin is a rectangular structure, and the size of the rectangular structure of the longitudinal section of the first surrounding purlin is 900mm-1100mm*8mm-9mm.

[0018] Further, the second surrounding purlin is connected with the circular foundation pit anchor cable, and the second surrounding purlin is used as an anchor head of the circular foundation pit anchor cable.

[0019] Further, the inner support layer comprises two oppositely arranged inner supports, the inner support is a V-shaped structure, and the three ends of the V-shaped structure of the inner support are arranged on the surrounding purlin.

[0020] Further, the longitudinal section of the inner support is a rectangular structure, and the size of the rectangular structure of the longitudinal section of the inner support is 700mm-800mm*600mm-700mm.

[0021] Further, a plurality of anchor rods are further included, and the anchor rods are arranged in the side of the foundation pit and below the foundation pit anchor cable.

[0022] The construction method of the utility model comprises the following steps: first, bite piles are constructed, then high-pressure rotary jet piles are constructed, after the pile foundation is detected and qualified, rotary digging piles are used to construct the foundation pit corbel, after the strength meets the design requirements, the soil above the inner support layer is excavated, after the soil is excavated to the bottom of the first surrounding purlin, the first surrounding purlin and the inner support layer are constructed, after the strength of the surrounding purlin meets the design requirements, the soil above the second surrounding purlin is excavated by using a long-arm excavator, after the construction of the second surrounding purlin is completed and the strength meets the design requirements, the soil above the third support is excavated by using a small excavator, the first anchor cable is constructed after the first anchor cable position is excavated, and the anchor rod is inserted and punched, the net is hung, and the concrete is sprayed for protection while the soil is excavated below the elevation of-34.4m.

[0023] Compared with the prior art, the utility model has the beneficial effects that: the utility model can flexibly adjust the configuration of the supporting pile, the surrounding purlin, the anchor rod and other supporting systems according to different foundation pit depths, soil conditions and underground water levels, and is suitable for various complex geological and hydrological conditions. The supporting pile adopts a double-layer supporting pile structure, the inner circle bite pile and the outer circle high-pressure rotary jet pile are combined, the supporting mode not only has strong supporting capacity, but also can effectively prevent underground water permeation, and provides a safer solution for deep foundation pit construction. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 It is a whole structure schematic view of the utility model;

[0025] Fig. 2 is a plan view of the utility model;

[0026] Fig. 3 is a partial view of the inner ring interlocking pile of the utility model, wherein A represents a plain pile, and B represents a reinforced concrete pile.

[0027] Among them, 1-interlocking pile, 2-high pressure rotary jet pile, 3-foundation pit crown beam, 4-enclosure purlin, 41-first enclosure purlin, 42-second enclosure purlin, 5-inner support layer, 6-foundation pit anchor cable, 7-anchor rod. DETAILED DESCRIPTION

[0028] The specific embodiments of the utility model will be described in detail below. Figs. 1 to 3 In the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model.

[0029] The terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features; in the description of the utility model, unless otherwise specified, the meaning of "multiple" is two or more.

[0030] EMBODIMENT

[0031] As shown in Fig. 1 , Fig. 2 , a pile-anchor support deep foundation pit combined support structure, comprising a plurality of interlocking piles 1, a plurality of high-pressure rotary jet piles 2, a foundation pit crown beam 3, a plurality of enclosure purlins 4, a plurality of inner support layers 5 and a plurality of foundation pit anchor cables 6.

[0032] The plurality of interlocking piles 1 are used to be sequentially arranged on the side of the foundation pit to form an inner ring enclosure, the plurality of high-pressure rotary jet piles 2 are used to be sequentially arranged on the side of the foundation pit and located outside the inner ring enclosure and in contact with the outer side of the inner ring enclosure to form an outer ring enclosure, the foundation pit crown beam 3 is fixed on the interlocking pile 1 and used to span the top of the foundation pit, the plurality of enclosure purlins 4 are arranged on the interlocking pile 1 from top to bottom, the plurality of inner support layers 5 are arranged one by one on the plurality of enclosure purlins 4 and used to support the inner ring enclosure, and the plurality of foundation pit anchor cables 6 are used to be buried in the side of the foundation pit and connected with the enclosure purlin 4 located at the lower part of the interlocking pile 1.

[0033] Preferably, the longitudinal section of the foundation pit capping beam 3 is a rectangular structure, and the rectangular structure dimensions of the longitudinal section of the foundation pit capping beam 3 are 1100mm-1300mm × 7mm-8mm. In this embodiment, the foundation pit capping beam 3 is a C30 reinforced concrete rectangular beam with an elevation of -11.7 and dimensions of 1200mm × 800mm.

[0034] Preferably, the waler 4 includes a first waler 41 and a second waler 42. There are at least two first walers 41, which are spaced apart from top to bottom on the upper part of the interlocking post 1, and there is at least one second waler 42, which is located on the lower part of the interlocking post 1.

[0035] Preferably, the longitudinal section of the first waler 41 is a rectangular structure, and the rectangular structure dimensions of the longitudinal section of the first waler 41 are 900mm-1100mm × 8mm-9mm. In this embodiment, the first waler 41 adopts a rectangular longitudinal section C30 reinforced concrete beam with elevations of -14.8m, -18.5m, and -22.2m, and the waler dimensions are 1000mm × 900mm.

[0036] Preferably, the second waler 42 is connected to the circular foundation pit anchor cable 6, and the second waler 42 is used as the anchor head of the circular foundation pit anchor cable 6.

[0037] Preferably, each inner support layer 5 includes two opposing inner supports, which are V-shaped structures, with all three ends of the V-shaped structure of the inner support set on the waler 4. In this embodiment, there are three inner support layers 5, with spacings of 3.1m, 3.7m, and 3.7m, respectively.

[0038] Preferably, the longitudinal section of the internal support is a rectangular structure with dimensions of 700mm-800mm × 600mm-700mm. The figure-eight brace is a C30 reinforced concrete rectangular beam with dimensions of 800mm × 700mm.

[0039] Preferably, the system also includes multiple anchor bolts 7, all of which are embedded in the side of the foundation pit and located below the anchor cable 6. Anchor bolts 7 are installed at random locations if the rock strata are fractured or if unfavorable structural surfaces are encountered.

[0040] The construction method of the above embodiment is as follows:

[0041] First, construct the interlocking pile 1, then proceed with the high-pressure jet grouting pile 2 construction, as follows: Fig. 3 As shown, the construction of interlocking pile 1 adopts a 560 rotary drilling rig. Plain piles are constructed first, followed by reinforced concrete piles. After the interlocking pile 1 reaches the design strength, a high-pressure jet grouting machine is used to construct the jet grouting pile 2 water-stop curtain around the interlocking pile 1 using the triple pipe method.

[0042] After the pile foundation is detected and qualified, the rotary digging pile top constructs the foundation pit crown beam 3, the strength satisfies the design requirement, excavates the earthwork above the inner support layer 5, adopts manual excavation, the earthwork is first transferred to the 30m range outside the foundation pit, then is uniformly loaded by the excavator Concentration is transported to the waste dump, and the subsequent excavation of earth and stone is all according to this mode of abandonment and transportation.

[0043] After the earthwork is excavated to the bottom of the first surrounding purlin 4 at the design elevation, the first surrounding purlin 4 and the inner support layer 5 are constructed, the strength of the surrounding purlin 4 satisfies the design requirement, the second surrounding purlin 4 above the earthwork is excavated by manual operation in cooperation with the long arm excavator, and the long arm excavator is used for excavation. After the construction of the second surrounding purlin 4 is completed, the strength satisfies the design requirement, the third surrounding purlin 4 above the earthwork is excavated by manual operation in cooperation with the small excavator, the 10t gantry crane vertically takes earth, and a steel ladder is arranged on site for personnel to go up and down the foundation pit.

[0044] The first anchor cable 6 is constructed, the 10t gantry crane takes earth, and the limited space operation is considered in this stage, and a ventilation pipeline is additionally arranged in the field. From the elevation-34.4m below, the anchor rod 7 is continuously inserted and punched, the net is sprayed and the concrete is protected while excavating. The pit bottom 30cm is manually leveled to ensure that it is not overdeep and not underexcavated, and the foundation bearing capacity test and foundation pit acceptance are carried out within 48h after excavation is completed, and the main structure operation is carried out only after the qualified.

[0045] The above-described specific embodiments further specifically illustrate the purpose, technical scheme and beneficial effects of the utility model, and it should be understood that the above-described specific embodiments are only specific embodiments of the utility model, and do not limit the utility model, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model are included in the protection scope of the utility model.

Claims

1. A combined support structure of a deep foundation pit supported by pile anchors, characterized in that, The utility model relates to a kind of foundation pit support structures, including: Multiple bite piles (1) are used to be sequentially arranged on the side of foundation pit, and form inner ring enclosure; Multiple high-pressure rotary jet piles (2) are used to be sequentially arranged on the side of foundation pit, and are located outside the inner ring enclosure and contact with the outer side of the inner ring enclosure, forming outer ring enclosure; Foundation pit crown beam (3) is fixed on bite pile (1), and is used to span on the top of foundation pit; Multiple surrounding purlins (4) are arranged on bite pile (1) from top to bottom at intervals; Multiple layers of inner support layer (5) are arranged on multiple surrounding purlins (4) one by one, for supporting the inner ring enclosure; Multiple foundation pit anchor cables (6) are used to be buried in the side of foundation pit, and are connected with surrounding purlin (4) located in the lower part of bite pile (1).

2. A combined support structure for deep foundation pit of pile-anchor with support, according to claim 1, characterized in that, The longitudinal section of the foundation pit crown beam (3) is a rectangular structure, and the size of the rectangular structure of the longitudinal section of the foundation pit crown beam (3) is 1100mm-1300mm×7mm-8mm.

3. A combined support structure for deep foundation pit of pile-anchor with support, according to claim 1, characterized in that, The surrounding purlin (4) includes: First surrounding purlin (41) is arranged on the upper part of bite pile (1) at intervals from top to bottom, and at least two surrounding purlins are arranged; Second surrounding purlin (42) is arranged on the lower part of bite pile (1), and at least one surrounding purlin is arranged.

4. A combined support structure for deep foundation pit of pile-anchor with the claim 3, characterized in that, The longitudinal section of the first surrounding purlin (41) is a rectangular structure, and the size of the rectangular structure of the longitudinal section of the first surrounding purlin (41) is 900mm-1100mm×8mm-9mm.

5. A combined support structure for deep foundation pit of pile-anchor with support, according to claim 3, characterized in that, The second surrounding purlin (42) is connected with the circular foundation pit anchor cable (6), and the second surrounding purlin (42) is used as the anchor head of the circular foundation pit anchor cable (6).

6. A combined support structure for deep foundation pit of pile-anchor with support, according to claim 1, characterized in that, The inner support layer (5) includes two oppositely arranged inner supports, and the inner support is a V-shaped structure, and the three ends of the V-shaped structure of the inner support are arranged on the surrounding purlin (4).

7. A combined support structure for deep foundation pit of pile-anchor with support, according to claim 6, characterized in that, The longitudinal section of the inner support is a rectangular structure, and the size of the rectangular structure of the longitudinal section of the inner support is 700mm-800mm×600mm-700mm.

8. A combined support structure for deep foundation pit of pile-anchor with support, according to claim 1, characterized in that, It also includes multiple anchor rods (7), and the anchor rod (7) is used to be buried in the side of foundation pit, and is located below the foundation pit anchor cable (6).

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