CN206034454U - Supporting construction - Google Patents

Abstract

The utility model discloses a support structure, which comprises a soil nail wall slope support structure arranged at the shallow pit of the foundation pit and a pile bottom anchoring pile row support structure arranged at the deep pit of the foundation pit; The slope support structure includes several soil nails and the sprayed concrete surface layer connected with several soil nails; the support structure of row piles anchored at the bottom of piles includes more than three rows of piles, and the support piles of adjacent rows of piles are connected by transverse connecting beams. The supporting piles on the same row of piles are connected through the longitudinal crown beam at the top of the column; all supporting piles or part of the supporting piles in the last row of piles are provided with anchor rods or I-beams. The utility model has strong anti-overturning ability, convenient construction and short construction period.

Description

a support structure

technical field

The utility model belongs to the field of civil engineering, and in particular relates to a support structure, which is suitable for excavation and support of deep foundation pits with strict displacement control, limited space occupied by the support structure and relatively large depth.

Background technique

In recent years, urban construction has sprung up like mushrooms after a spring rain, and urban construction land has become increasingly scarce, prompting buildings (structures) to continue to develop into underground spaces, and the corresponding deep underground foundation pits have also been dug deeper and deeper. The excavation area has also been further increased. In addition, due to dense buildings and scarce land, there are houses, subways, etc. around the foundation pit, which makes the environment of the foundation pit site and engineering geological conditions more complicated, and the types of foundation pits are more diverse. There are higher requirements for the safety, convenience of construction and technical conditions.

The existing supporting structures mainly have the following deficiencies:

(1) The support depth of the pile row structure is limited. The support depth of a single row of cantilever piles should not exceed 6m, and the support depth of a double row of piles should not exceed 12m. As the depth increases, the side wall of the foundation pit will be deformed greatly. Problems such as excessive pile displacement and weak anti-overturning ability.

(2) The use of internal support row pile support structure requires a large area of support beams and columns with complex structures to be installed in the foundation pit, which requires a large area of construction space, causing inconvenience to the excavation of the earthwork in the pit and the construction of the main structure. In addition, during the construction period, the foundation pit needs to be excavated in layers, and the supporting components are constructed layer by layer. After the excavation of the earthwork, the supports need to be removed and replaced, and the construction period is long.

(3) The pile-anchor support structure is adopted. The construction of anchor rods requires no obstacles in the ground, and the length of the anchor rods is tens of meters, requiring a large accommodation space, which often exceeds the scope of the building red line, especially in adjacent existing buildings or The excavation of the foundation pit of the subway is even more inapplicable.

Therefore, due to the limitations of factors such as excavation depth, construction period, underground space, and geological conditions, it is difficult to meet actual needs with the existing pile row structure, internal support, or pile-anchor support structure.

Utility model content

The purpose of this utility model is to provide a support structure with strong anti-overturning ability, convenient construction and short construction period, which can solve the problem that the existing support structure cannot be applied to deep foundation pit excavation depth, and the underground space is affected by the adjacent existing buildings. The question of limitations.

The technical scheme adopted in the utility model is:

A support structure, comprising a soil nail wall grading support structure arranged at the shallow pit of the foundation pit and a pile bottom anchoring row pile support structure arranged at the deep pit of the foundation pit;

The grading support structure of the soil nail wall includes a number of soil nails arranged in the soil layer, and a sprayed concrete surface layer connected with the soil nails, and the shotcrete surface layer is arranged on the slope;

The pile bottom anchoring row pile support structure includes more than three rows of piles, and the supporting piles of adjacent rows of piles are connected by transverse connecting beams (that is, each row of piles perpendicular to the edge direction of the foundation pit is connected by horizontal connecting beams), The support piles on the same row of piles are connected by the vertical crown beam on the top of the column (that is, the same row of support piles parallel to the edge of the foundation pit are connected by the vertical crown beam on the top of the column); Vertical crown-beam connection at the top of the column; vertical anchor rods or I-beams are arranged in all or part of the support piles in the last row of piles.

According to the above scheme, the row of piles has three rows, which are the front row of piles, the middle row of piles, and the rear row of piles, and cement-soil mixing piles are arranged between the rear row of piles and the slope support structure of the soil nail wall; The supporting piles of the rows of piles can be straight piles or expanded piles; if there is soft soil on the site, the soft soil between the piles can be reinforced by setting high-pressure rotary grouting piles between each row of piles. This structure can increase the anti-overturning ability of the supporting structure.

According to the above scheme, the soil nail wall grading support structure is located on the side wall of the foundation pit behind the top of the last row of piles; the side wall of the foundation pit can be sloped in two or more stages, and each level A soil nail wall grading support structure is provided to increase the anti-overturning capability of the support structure.

According to the above scheme, the supporting piles of the front row of piles, the middle row of piles, and the rear row of piles are not equal in diameter and inconsistent in length; Adapt to different environments.

According to the above scheme, each support pile of the front row of piles, the middle row of piles and the rear row of piles is vertically arranged; or

Each support and protection pile of the front row of piles and/or the rear row of piles is inclined to make the force more reasonable;

According to the above scheme, steel sleeves are arranged in all the support piles or a part of the support piles of the rear row of piles; the anchor rod or the I-beam is placed in the steel sleeve, and one end stretches out of the steel sleeve; the anchor rod or There is cement slurry between the I-beam and the steel sleeve; the number of anchor rods or I-beams in the support pile can be set to single or multiple according to the site conditions, so as to facilitate installation and increase the overturning resistance of the support structure ability.

According to the above scheme, the anchor rod or I-beam protruding from the steel sleeve is connected to the anchor section, the anchor section is embedded in the rock formation or good bearing layer under the pile, and the free end of the anchor rod or I-beam is anchored to the longitudinal crown of the pile top. Beams to increase the anti-overturning capability of the supporting structure.

According to the above scheme, more than one reaming anchor is provided on the support piles of the rear row of piles, so as to improve the pull-out resistance of the support piles and increase the anti-overturning ability.

According to the above scheme, the gap between the transverse connecting beam and the longitudinal crown beam at the top of the pile is provided with a reinforced concrete cover plate with the same thickness as the beam.

If the geological conditions of the site are poor, the excavation depth is large, and factors such as the long-side effect need to be considered, counter bracing, corner bracing or diagonal bracing can be set on the longitudinal crown beam of the pile top, and the horizontal distance L between the counter bracing and corner bracing is 40-50m to increase the strength of the supporting structure.

The beneficial effects of the utility model are:

Through the connection of the soil nail wall grading support structure and the pile bottom anchorage pile support structure, and the use of multiple rows of piles, the support structure can be applied to deep foundation pits with a depth of 16~20m, and has anti-overturning ability Strong, convenient construction, short construction period;

With strong applicability and high cost performance, it can solve the technical problems of deep excavation of foundation pits and the underground space is limited by adjacent existing buildings.

The supporting piles of the rear row of piles are provided with reaming anchors, so that the pullout resistance of the supporting piles of the rear row of piles is improved; Its pull-out resistance optimizes the entire support structure, which can effectively improve the anti-overturning ability of the support structure and the overall rigidity of the structure;

It can reduce the occupation of underground space and expand the scope of application. It is especially suitable for situations where there are existing buildings around the foundation pit where conventional oblique anchors cannot be used. It has little impact on the surrounding environment of the foundation pit and better avoids damage to surrounding houses. Damage to foundations, underground pipelines, lines and other underground structures;

Inside the foundation pit, only a few pairs of braces and corner braces are set on the longitudinal crown beam of the pile top, or no inner braces can be set according to the site conditions, which facilitates the excavation construction of the earthwork in the pit, and the excavation and transportation of the earthwork is fast, which reduces the construction cost The construction of the main structure is convenient, the construction period is shortened, and the comprehensive economic benefits are improved.

Description of drawings

The utility model will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is the plan view of the utility model support structure;

Fig. 2 is the A-A sectional view of Fig. 1 (the rear row of piles is provided with anchor rods);

Figure 3, Figure 4, and Figure 5 are schematic diagrams of the arrangement of single, double, and four bolts respectively;

Fig. 6 is the A-A sectional view of Fig. 1 (the rear row of piles is provided with I-beam);

Fig. 7 is a schematic diagram of the layout of the I-beam;

Fig. 8 is a plan view under the condition of setting up the pair of top braces and corner braces;

Fig. 9 is the structural representation that front row pile is inclined pile;

Figure 10 is a schematic diagram of the structure in which both the front row of piles and the rear row of piles are inclined piles.

The labels in the figure are: 1-Three rows of piles; 1.1-Front row of piles; 1.2-Middle row of piles; 1.3-Back row of piles; 2-Pile top longitudinal crown beam; ;5-Anchor rod; 6-Cement-soil mixing pile; 7-Shotcrete surface layer; 8-Soil nail; 9-Foundation pit bottom; 10-Steel casing; Backing plate; 14-anchor section; 15-reaming anchor; 17-pair of top brace; 18-angular brace.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

Referring to Figures 1-7, a support structure includes a soil nail wall grading support structure arranged at the shallow pit of the foundation pit and a pile bottom anchoring row pile support structure arranged at the deep pit of the foundation pit, forming a ladder support structure;

The slope support structure of the soil nail wall includes a number of soil nails 8 arranged in the soil layer, and a shotcrete surface layer 7 connected to the plurality of soil nails 8, and the shotcrete surface layer 7 is arranged on the slope;

The pile bottom anchorage pile support structure includes more than three rows of piles. In a preferred embodiment, there are three rows of piles, which are respectively the front row of piles 1.1, the middle row of piles 1.2, the rear row of piles 1.3, and the three rows of piles. The piles are all inserted into the bottom of the foundation pit 9; of course, in order to increase the anti-overturning ability, multiple rows of piles such as four rows and five rows of piles can also be set; Each row of piles includes a plurality of supporting piles; the supporting piles of adjacent rows of piles are connected by horizontal connecting beams 3, and the supporting piles on the same row of piles are connected by vertical crown beams 2 on the top of columns; The beam 3 connects the longitudinal crown beam 2 on the column top of all rows of piles in the horizontal direction, and a reinforced concrete cover plate 4 with the same thickness as the beam is provided in the gap between the horizontal connecting beam 3 and the longitudinal crown beam 2 on the pile top; Steel sleeves 10 are arranged in all the support piles or part of the support piles of pile 1.3, and anchor rods 5 or I-beams 11 are installed in the steel sleeves 10; one end of the anchor rods 5 or I-beams 11 extends out of the steel sleeves After 10, it is connected with the anchor section 14, the anchor section 14 is embedded in the rock formation or good bearing layer under the pile, and the free end of the anchor rod 5 or the I-beam 11 is anchored to the longitudinal crown beam 2 on the top of the pile through the anchor 12 and the backing plate 13 Be provided with cement slurry between the anchor rod 5 or the I-beam 11 and the steel sleeve 10; the quantity of the anchor rod 5 or the I-beam 11 in the steel sleeve 10 can be set to single or multiple according to the site conditions, See Figure 3, Figure 4, Figure 5, and Figure 7 for details.

When the groundwater in the scope of the foundation pit is rich and the soil layer has strong water permeability, cement-soil mixing piles 6 can be arranged between the rear row of piles 1.3 and the slope support structure of the soil nail wall; in order to enhance the pullout resistance, the rear row of piles The supporting piles of 1.3 can be straight piles or expansion piles; of course, more than one reaming anchor 15 can also be set on the rear row of piles 1.3.

In this embodiment, the slope support structure of the soil nail wall is located on the side wall of the foundation pit on the rear side of the pile top of the rear row of piles 1.3; Soil nail wall grading support structure.

In the utility model, the supporting pile diameters of the front row of piles 1.1, the middle row of piles 1.2, and the rear row of piles 1.3 can be equal or unequal, and the lengths can be consistent or inconsistent; for example, in Fig. 9 and Fig. 10, the middle The support pile of row pile 1.2 is shorter than the support pile of front row pile 1.1, rear row pile 1.3. The supporting piles of the front row of piles 1.1, the middle row of piles 1.2 and the rear row of piles 1.3 can be set vertically, as shown in Figure 2 and Figure 6, of course, they can also be set in a combined way (inclined, vertical), such as the front row of piles 1.1 The supporting piles in the middle row of piles 1.2 and the rear row of piles 1.3 are arranged vertically, see Figure 9; of course, the supporting piles of the front row of piles 1.1 and the rear row of piles 1.3 are arranged obliquely, and the middle row of piles The support piles of 1.2 are set vertically, see Figure 10.

Referring to Fig. 8, if the geological conditions of the site are poor, the excavation depth is large, and factors such as the long-side effect need to be considered, a pair of top braces 17, corner braces 18 or diagonal braces can be set on the longitudinal crown beam 2 of the pile top. In order to increase the anti-overturning moment, the horizontal distance L between the top brace 17 and the corner brace 18 is controlled between 40-50m.

In the utility model, the distance between the front and back of each row of piles and the distance between the piles in each row of piles can be adjusted according to the actual conditions of the site environment, stratum geology, etc. If the excavation depth is further increased and the geological conditions are poor, it can also be considered The middle row of piles 1.2 and the front row of piles 1.1 are arranged in the form of rear row of piles 1.3. The quantity of the reaming anchors 15 arranged on the pile body of the rear row can be determined according to the required anchoring force.

Implementation steps of the present utility model: first construct the slope support structure of the soil nail wall at the shallow pit position, support while excavating, drill holes at fixed points, insert soil nails 8, inject grout, and then spray the concrete surface layer 7, Excavate the soil to the design elevation of the top of the row of piles. Afterwards, three rows of piles 1 are constructed, and before the rear row of piles 1.3 is poured with concrete, a steel casing 10 is inserted into the supporting pile body of the rear row of piles 1.3, and an anchor rod 5 or an I-beam 11 is inserted into the steel casing 10. Then carry out underwater grouting to the anchor section 14 connected with the anchor rod 5 or the I-beam 11, then construct the pile top longitudinal crown beam 2, transverse connecting beam 3, reinforced concrete cover plate 4, and then anchor the free end of the anchor rod 5 On the pile top longitudinal crown beam 2 of rear row pile 1.3. Then excavate the earthwork of the deep pit in layers and sections. After excavating to the pit bottom elevation, construct the main structure of the deep pit part. The underground main structure of this part is implemented to the elevation of three rows of piles and one pile top Top bracing and corner braces, first remove them), backfill the foundation pit at the deep pit, and then construct the main structure of the shallow foundation pit. After the construction of all underground main structures is completed, the foundation pit can be backfilled.

The utility model has strong anti-overturning ability, good overall stability, high support rigidity, and can better control the horizontal displacement of the pile top; the support structure occupies less space, has a deeper applicable depth than conventional double-row piles, and has less or less internal support settings. There is no need for internal support, and it is convenient for earthwork construction in the pit, which greatly shortens the construction period and reduces the project cost.

It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present utility model.

Claims (10)

1. a kind of supporting construction, it is characterised in that：Including the soil nail wall sloping timbering structure and setting that are arranged at foundation ditch shallow hole Stake bottom anchoring Row Piles Supporting Structure at foundation ditch dell；

The gunite concrete surface layer that the soil nail wall sloping timbering structure is included some soil nailings and is connected with some soil nailings；

The stake bottom anchoring Row Piles Supporting Structure includes the campshed of more than three rows, and the support pile of adjacent campshed is connected by horizontal coupling beam Connect, the support pile on same row campshed is by the Guan Liang connection of capital longitudinal direction；All support piles of campshed or one are arranged at last Anchor pole or I-steel is provided with branch's fender pile.

2. supporting construction according to claim 1, it is characterised in that：The campshed has three rows, respectively front campshed, middle row Stake, rear campshed, are provided with cement mixing method between rear campshed and soil nail wall sloping timbering structure；High pressure is provided between each campshed Rotary churning pile.

3. supporting construction according to claim 1 and 2, it is characterised in that：The soil nail wall sloping timbering structure is located at most On foundation pit side-wall on rear side of latter row campshed stake top；Foundation pit side-wall can adopt two-stage or multistage slope, be equipped with every grade of slope Soil nail wall sloping timbering structure.

4. supporting construction according to claim 2, it is characterised in that：The front campshed, middle campshed, the support pile of rear campshed Stake footpath is unequal, cause different in size.

5. supporting construction according to claim 4, it is characterised in that：The front campshed, middle campshed, each supporting of rear campshed Stake is vertically arranged；Or

Each support pile of the front campshed and/or rear campshed is obliquely installed.

6. the supporting construction according to claim 2,4 or 5, it is characterised in that：All support piles or one of the rear campshed Steel bushing is provided with the support pile of part；Anchor pole or I-steel are placed in steel bushing, and its one end stretches out steel bushing.

7. supporting construction according to claim 6, it is characterised in that：The anchor pole or I-steel and anchor for stretching out steel bushing Gu section connects, under the embedded stake of anchoring section in rock stratum or good supporting course, anchor pole or I-steel free end are anchored in stake top longitudinal direction In Guan Liang.

8. supporting construction according to claim 6, it is characterised in that：The support pile of the rear campshed is provided with more than one Reaming anchoring body.

9. supporting construction according to claim 1, it is characterised in that：Space between horizontal coupling beam and stake top longitudinal direction Guan Liang It is provided with reinforced concrete cover plate.

10. supporting construction according to claim 9, it is characterised in that：Stake top longitudinal direction Guan Liang is provided with to shoring, angle Support or diagonal brace, level interval L to shoring with angle brace is 40～50m.