CN212477698U - Construction structure of large-area soil-squeezing grouped piles in soil-squeezing sensitive area - Google Patents

Abstract

The utility model provides a construction structure of large-area soil-squeezing grouped piles in a soil-squeezing sensitive area, which relates to the technical field of foundation construction, and comprises a large-area pre-stressed tubular pile grouped pile area; the pile group area is divided into a plurality of subareas, deep isolation trenches are arranged on the periphery of the pile group area and the boundary of the subareas, a plurality of stress release holes are arranged in each subarea, and the subareas are divided into a plurality of subareas. The utility model discloses a mode that the subregion was kept apart, the piecemeal release, the crowded native stress that produces the construction of large tracts of land crowd's stake is broken up into whole parts, can effectively ensure adjacent existing building basement or deep foundation safety.

Description

Construction structure of large-area soil-squeezing grouped piles in soil-squeezing sensitive area

Technical Field

The utility model relates to a construction structures of crowded native crowd's stake of crowded sensitive district large tracts of land belongs to foundation construction technical field.

Background

The prestressed pipe pile is produced industrially, has high pile body strength, reliable quality, strong bearing capacity of a single pile, high construction mechanization degree and high construction speed, is widely applied to industrial and civil building engineering foundations, and has wide development prospect. However, due to the soil squeezing effect in the pile sinking process of the prestressed pipe pile, soil around the pile is easy to bulge and displace, the safety of adjacent pile bodies and adjacent underground buildings, structures, deep foundations, surrounding municipal roads and pipelines is damaged, and the effect is particularly obvious when pile group construction is carried out in a soft soil area.

In order to effectively control the soil squeezing hazard generated by the construction of the prestressed pipe pile, the measures of soil taking, excavation of anti-squeezing ditches and the like are performed by commonly pre-opening holes (including pile position pre-leading holes, stress release holes arranged among piles and the like) in the engineering, and when the pile arrangement area of the pile foundation to be constructed is small, the total number of piles is small, and the periphery of the construction site is only a municipal road and a shallow municipal pipeline, the measures can effectively offset the soil squeezing effect generated in the construction process of the pile foundation, so that the safety of the periphery environment in the construction process is ensured.

However, when the pile foundation to be constructed is a large-area prestressed pipe pile, and the construction site is sensitive to the soil squeezing effect, for example, a deep soft soil layer exists on the surface of the pile, and the project is close to the existing underground construction, structure or deep foundation, the soil squeezing effect generated by pile group construction may cause major accidents such as adjacent underground construction, structure floating, damage, water permeation, ground house inclination, adjacent existing pile body shearing and the like, which seriously endangers the life of people and the safety of public and private properties, and must be controlled in a key way. Under this unfavorable condition, if still take foretell conventional measure, required trompil soil sampling quantity is very amazing, and behind a large amount of trompil soil sampling in advance, the construction site suffers serious damage, seriously influences pile foundation construction equipment mobility and material transfer efficiency, causes the efficiency of construction to reduce by a wide margin, and construction measure cost is raised by a wide margin. In addition, it is difficult to effectively protect existing underground structures, structures or deep foundations nearby by digging only the shallow anti-extrusion ditches.

The present application was made based on this.

SUMMERY OF THE UTILITY MODEL

In order to solve the above-mentioned defect that exists among the prior art, the utility model provides a construction structures of crowded native grouplet of crowded sensitive district large tracts of land for crowded native grouplet of sensitive district large tracts of land of crowded soil can be normally under construction high-efficiently.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a construction structure of large-area soil-squeezing grouped piles in a soil-squeezing sensitive area comprises a large-area prestressed pipe pile grouped pile area; the pile group area is divided into a plurality of subareas, deep isolation trenches are arranged on the periphery of the pile group area and the boundary of the subareas, a plurality of stress release holes are arranged in each subarea, and the subareas are divided into a plurality of subareas.

Furthermore, the width of the deep isolation trench is determined according to the diameter of a drill bit of common stirring equipment, preferably 750-850mm, the depth of the isolation trench is determined according to the thickness of the soft soil layer and the length of the grouped piles, generally 20-25m and not less than 2/3 pile length, the drilling speed of the stirrer is about 1.5 m/min, and the water spraying pressure is 0.5-1 MPa.

Furthermore, the stress release holes are arranged along the central axis of each partition, the aperture is determined according to the diameter of a drill bit of common stirring equipment, generally 600-700mm, the depth of the holes is equivalent to that of the deep isolation trench, generally 20-30m, and a single-shaft drilling pile machine is adopted for construction.

The utility model discloses construction process and principle of construction structures: dividing large-area prestressed pipe pile groups into a plurality of subareas, and arranging deep isolation trenches at the periphery of the pile groups and at the positions of subarea lines to prevent shallow and deep soil squeezing stress generated by pile group construction of each subarea from diffusing to the periphery of the pile groups and among the subareas. In each subarea, a conventional stress release hole is locally arranged to work together with the deep isolation trench to digest the soil-squeezing stress generated by pile group construction in each subarea, so that large-area soil-squeezing pile groups in a soil-squeezing sensitive area can be constructed normally and efficiently.

The pile group construction is carried out zone by zone according to the sequence of zones, and the pile group of each zone is divided into a plurality of blocks and is arranged from the center to the periphery. In addition, during construction, soil displacement monitoring is carried out on the periphery of the grouped piles, a monitoring emergency plan is formulated, pile sinking speed is dynamically adjusted or deep isolation ditches are repeatedly stirred according to monitoring data, and safety of adjacent underground constructions, structures or deep foundations is further ensured.

The utility model discloses can realize following technological effect:

(1) the mode of partition isolation and block release is adopted, the soil-squeezing stress generated by the construction of large-area pile groups is broken into parts, so that the large-area soil-squeezing pile groups in the soil-squeezing sensitive area can be constructed normally and efficiently.

(2) On the basis of adopting deep isolation trench, only need complementary a small amount of stress release hole of seting up, it is little to the influence in construction place, and it is few to arrange the earthwork volume outward, does not influence tubular pile efficiency of construction and construction measure expense low.

Drawings

FIG. 1 is a plan view of the present embodiment;

fig. 2 is a schematic view of the construction structure of large-area soil-squeezing grouped piles in the soil-squeezing sensitive area according to the present invention applied to the project of the present embodiment;

fig. 3 is a schematic view of the construction sequence of the area 1 in this embodiment.

Description of the labeling: the three-layer is supplementary with room 1, individual layer super large exhibition room 2, and supplementary room foundation pile 3, exhibition room crowd's stake 4, deep isolation ditch 5, stress release hole 6.

Detailed Description

In order to make the technical means and technical effects achieved by the present invention clearer and more complete, a preferred embodiment is provided, and the following detailed description is made with reference to the accompanying drawings:

as shown in fig. 1, the utility model discloses a great exhibition hall of a great scale international exhibition project of preferred embodiment length 378 meters, width 90 meters, height 27 meters, exhibition hall north and south side is three 3 layers of auxiliary rooms 1, the middle part is single-layer great exhibition hall 2, wherein auxiliary room pile foundation 3 adopts PHC prestressed pipe pile, pile diameter 600mm, pile length 44 or 48 meters, pile number 870; the super-large exhibition hall 2 has high requirement on ground bearing capacity, the terrace of the super-large exhibition hall adopts a reinforced concrete plate structure supported by a group of piles 4, the group of piles 4 are PHC prestressed pipe piles, the diameter of each pile is 400mm, the length of each pile is 31 or 33 meters, and the number of the piles is 2149. Because the exhibition hall is positioned in a muddy soft soil area, the thickness of a soft soil layer is thick (about 20 meters), and the water content is high (about 50 percent), under the geological condition, the construction of the grouped piles 4 is easy to cause the inclination, the cracks and the deflection of adjacent pile bodies, and the damages to municipal roads and pipelines at the north side and the west side of the exhibition hall are easy to cause, and how to control the soil extrusion hazard possibly generated by the construction of the large-area grouped piles is the difficulty of the construction of the pile foundation engineering of the project.

Under normal conditions, the construction of the engineering pile foundation is to construct the group piles 4 of the exhibition hall firstly and then construct the auxiliary house foundation piles 3 on the north and south sides, but because the engineering is short in construction period and high in construction progress requirement, a working surface is created for the construction of the auxiliary house main body as soon as possible, the engineering adopts the parallel propulsion mode of the auxiliary house foundation piles 3 and the group piles 4 of the exhibition hall for construction, because the number of the auxiliary house foundation piles 3 is relatively small, the construction propulsion speed is higher than that of the group piles 4 of the exhibition hall, the construction of the group piles 4 needs to ensure the safety of the auxiliary house foundation piles 3 which are firstly arranged, and the construction difficulty is further increased.

The above problem is well solved by the present embodiment.

As shown in fig. 2, in the construction structure of a large-area soil-squeezing grouped pile in a soil-squeezing sensitive area of this embodiment, a pile group 4 in an exhibition hall is divided into 6 subareas (1 area, 2 area, 3 area, 4 area, 5 area, 6 area), deep isolation ditches 5 are arranged on the periphery and the subarea line of the pile group 4, a row of stress release holes 6 is additionally arranged in the middle of each subarea, and each subarea is further divided into two subareas (1-a subarea and 1-b subarea, 2-a subarea and 2-b subarea, … …, 6-a subarea and 6-b subarea).

In the embodiment, the width of the deep isolation trench is 800mm, the depth is 22m, the construction is carried out by adopting a mode of in-situ soil cutting and stirring of a three-shaft stirrer, the drilling speed of the stirrer is about 1.5 m/min, a drill bit continuously sprays clean water in the stirring process so as to improve the consistency of the stirred soil body in the isolation trench, the drill bit is prevented from being blocked, and the water spraying pressure is kept at about 0.5-1 MPa.

In this embodiment, the stress release holes 6 are arranged along the central axis of each partition, the hole diameter is 650mm, the hole depth is 25m, and a single-shaft drilling pile machine is adopted for construction.

In this embodiment, the construction of the group piles 4 in the exhibition hall is performed from the 1 area to the six areas, the construction sequence of the group piles 4 in the 1 area is as shown in fig. 3, the 1-a block construction is performed firstly, the pile machine is in place in the middle of the block, the pile machine is arranged along the line 1 to the axis direction of the block, the pile machine returns to the middle of the block and is arranged along the line 2 to the auxiliary room direction, after the 1-a block division is completed, the pile machine moves to the middle of the 1-b block, the pile machine is arranged along the line 3 to the axis direction of the block, and the pile machine returns to the middle of the block and is arranged along the line 4 to the auxiliary room.

In this embodiment, after completing the construction of the area 1, the pile machine moves to the area 2, completes the construction of the group piles 4 partitioned into 2-a and 2-b according to the same line as the area 1, and then completes the construction of the group piles 4 of all the exhibition halls according to the same construction sequence by areas.

In the embodiment, in order to verify the process effect and prevent accidents, while the terrace pile is constructed, the inclination measuring holes are arranged on the periphery of the group of piles to monitor the displacement of the soil body, the monitoring and early warning value is that the single-day horizontal displacement exceeds 5mm, the accumulated displacement does not exceed 50mm, once the early warning value is exceeded, the deep isolation ditch at the displacement overrun part is immediately sprayed with water for re-stirring, and the process parameters such as pile pressing speed, water spraying pressure and the like are optimized and adjusted, and then construction is continued.

The utility model adopts the mode of partition isolation and block release, under the condition of parallel construction of the auxiliary house foundation pile and the exhibition hall floor pile, the whole soil-squeezing stress generated by the construction of the large-area floor pile is broken into parts, the overall construction arrangement of parallel construction of the auxiliary house and the exhibition hall pile foundation is effectively ensured, and the construction period is saved; on the basis of adopting deep isolation trench, only need a small amount of stress release holes of complementary seting up, it is few to arrange the earthwork volume outward, and is little to the influence in construction site, and the construction measure expense is low, and the efficiency of construction is high.

After the construction is finished, the third party detects that the proportion of the first-class piles of the engineering reaches more than 95 percent, no three-class piles exist, no damage to surrounding municipal facilities occurs, the technical measures are safe and reliable, and the safety of the adjacent deep foundation and the surrounding environment is effectively ensured.

The above is a detailed description of the technical solutions provided in connection with the preferred embodiments of the present invention, and it should not be assumed that the embodiments of the present invention are limited to the above description, and it will be apparent to those skilled in the art that the present invention can be implemented in a variety of ways without departing from the spirit and scope of the present invention.

Claims (3)

1. The utility model provides a construction structures of crowded soil crowd's stake of crowded soil sensitive area large tracts of land which characterized in that: comprises a large-area prestressed pipe pile group pile area; the pile group area is divided into a plurality of subareas, deep isolation trenches are arranged on the periphery of the pile group area and the boundary of the subareas, a plurality of stress release holes are arranged in each subarea, and the subareas are divided into a plurality of subareas.

2. The construction structure of the large-area soil-squeezing grouped pile in the soil-squeezing sensitive area as claimed in claim 1, wherein: the width of the deep isolation trench is 750-850mm, and the depth is 20-25 m.

3. The construction structure of the large-area soil-squeezing grouped pile in the soil-squeezing sensitive area as claimed in claim 1, wherein: the aperture of the stress release hole is 600-700mm, and the depth of the hole is 20-30 m.

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