CN111021391A

CN111021391A - Large-scale exhibition hall pile slab structure terrace in weak soil area

Info

Publication number: CN111021391A
Application number: CN201911375740.2A
Authority: CN
Inventors: 叶翔; 刘中华; 张晓鹏; 宋剑波; 沈建明; 郭卫国; 张玉奇; 杨波; 胡广龙; 姚盼盼; 管世林
Original assignee: Zhejiang Jinggong Steel Structure Group Co Ltd
Current assignee: Zhejiang Jinggong Steel Structure Group Co Ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-04-17

Abstract

The invention discloses a terrace with a large-scale exhibition hall pile plate structure in a soft soil area, which comprises a terrace pile driven into a soft soil foundation, wherein a pile cap is arranged on the terrace pile, a ground plate is paved on the pile cap, and the terrace pile, the pile cap and the terrace plate are anchored through steel bars to form an integral stress structure. The ground load (including the comprehensive pipe ditch part) of the exhibition hall is borne by the floor piles, the pile foundation has high bearing capacity, small sedimentation amount and reliable technology, the expected bearing capacity can be obtained only by driving the floor piles into a proper soil layer, and the sedimentation amount can be controlled to be very small, so that the problems of high requirement on the ground bearing capacity of the exhibition hall, long consolidation period of a soft soil foundation, large later sedimentation amount and uneven later sedimentation in pipe ditches and floor areas are effectively solved.

Description

Large-scale exhibition hall pile slab structure terrace in weak soil area

Technical Field

The invention relates to the technical field of soft soil foundation treatment, in particular to a large-scale exhibition hall pile plate structure terrace in a soft soil area.

Background

With the development of social economy, the exhibition economy becomes a new bright spot for developing modern service industry in China, the number of exhibitions and the exhibition area are increased year by year, and coastal cities continuously accelerate the construction of infrastructures such as large-scale exhibition halls and the like by virtue of excellent regional advantages, so that the exhibition economy becomes a leading sheep for developing the exhibition economy.

The large-scale exhibition hall terrace is loaded greatly, and subsides and requires rigorously, and the coastal area uses soft soil foundation as the main, has characteristics such as moisture content height, pore ratio are big, the compressibility is high, the water permeability is poor, often can not satisfy the bearing capacity and the settlement control requirement of large-scale exhibition hall terrace, needs consolidate the processing.

The conventional soft soil foundation treatment method includes a drainage consolidation method, a composite foundation method and the like. The drainage consolidation method has reliable technology and obvious treatment effect, but has long construction period, large transportation cost of the piled soil body and no environmental protection; the composite foundation method has the advantages of simple process and relatively high construction speed, but the construction quality control difficulty is high, the treatment effect is limited, the foundation settlement can be completed for years under the action of additional loads such as backfill soil, a mattress layer, a concrete layer and the like, and the settlement quantity is large, so that the normal use of an exhibition hall is influenced. In addition, in large-scale exhibition hall, the trench region is for excavating the soil unloading district, and the terrace region is backfilling loading district, and there must exist the inhomogeneous phenomenon of subsiding between the two, easily arouses terrace damage and electromechanical pipeline damage, and the later maintenance expense is great.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a large-scale exhibition hall pile plate structure terrace in a soft soil area.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a large-scale exhibition hall pile sheet structure terrace in soft soil area, is including driving into the terrace pile in the soft soil foundation, be provided with the pile cap on the terrace pile, the pile cap upper berth is equipped with the ground flat board, the terrace pile the pile cap the formation whole stress structure is gone into through the reinforcing bar anchor between the terrace board.

The terrace pile is driven into in the soft soil foundation, the terrace pile goes deep into and crouches the supporting layer down, establishes the pile cap on the terrace pile, directly lays the rigidity terrace plate on the pile cap, goes into through the reinforcing bar anchor between terrace pile, pile cap, the rigidity terrace plate and forms whole stress structure. The working mechanism of the structure is similar to that of a flat slab, the ground load (including the comprehensive pipe ditch part) of the exhibition hall is considered to be borne by the terrace piles during the structure calculation, and the contribution of the soil among the piles to the bearing capacity of the terrace is not considered.

Furthermore, the terrace piles are PHC pretensioned prestressed concrete pipe piles which are evenly arranged in two directions and vertically driven into the soft soil foundation.

Further, the terrace pile is a friction type pile or an end-bearing type pile, the pile diameter is not suitable to be too large due to more piles, generally 400-plus-500 mm, and the concrete pile diameter, pile length, pile distance vision upper load, geological conditions of project location and construction difficulty are determined after technical and economic comprehensive calculation and comparison.

Furthermore, the pile bottom of the terrace pile is provided with an opening type pile tip, the pile top is embedded into the pile cap by 50-100mm, the pile top is subjected to core filling treatment within the range of 1-2m, and the main reinforcement of the core filling reinforcement cage extends outwards and is anchored into the pile cap and the terrace plate. The size, the thickness and the reinforcing bar of the concrete pile cap are determined by calculation according to the upper load and the thickness of the rigid terrace plate, and the requirement of the rigid terrace plate and the pile cap on the punching resistance is met.

Further, the pile cap is of a square reinforced concrete structure, the bottom of the pile cap is provided with two-way reinforcing bars, and the main reinforcing bars are bent and upwards turned and anchored into the terrace plate.

Further, the lower part of the pile cap is provided with a first cushion layer which is 50-100mm thick plain concrete, the lower part of the first cushion layer is compacted backfill soil through rolling compaction, and brick moulds are arranged around the pile cap.

Furthermore, the floor slab is a reinforced concrete slab, the economic slab is 200-300 mm thick, and double-layer bidirectional reinforcing bars are arranged in the slab. The specific plate thickness and the size of the reinforcing bars are determined by calculation according to the upper load, the pile distance and the size of the pile cap, and the requirements of self bending resistance, punching resistance and local bearing capacity are met.

Further, the lower part of the rigid terrace plate is provided with a second cushion layer, the second cushion layer is a plain concrete cushion layer with the thickness of 100mm, and the lower part of the second cushion layer is backfilled soil compacted by rolling. The compaction degree is based on the requirement of walking and working of the terrace pile pressing equipment; the upper part of the floor slab is a building surface layer, and the method is not limited.

Further, at the integrated pipe ditch position, the terrace pile is arranged under the side plates on the two sides of the pipe ditch or arranged at the central position of the bottom plate of the pipe ditch. The arrangement of the terrace piles is locally adjusted at the position of the comprehensive pipe trench, so that the bearing capacity requirement of the comprehensive pipe trench is met. When the trench width is close the ground stake cloth interval, arrange the ground stake under the curb plate of trench both sides, when the trench width is narrower, can arrange the ground stake at trench bottom plate central point.

Further, when the terrace pile is arranged below side plates on two sides of the pipe ditch, the cap pile and the main reinforcement of the pile top core pouring steel reinforcement cage are directly anchored into the bottom plate of the pipe ditch.

In summary, compared with the prior art, the invention has the following beneficial effects:

1. the ground load of the exhibition hall (including the comprehensive pipe trench part) is completely born by the terrace pile, the pile foundation has high bearing capacity, small settlement and reliable technology, the expected bearing capacity can be obtained only by driving the terrace pile into a proper soil layer, and the settlement can be controlled to be very small, thereby effectively solving the problems of high requirement on the ground bearing capacity of the exhibition hall, long consolidation period of a soft soil foundation, large later settlement and uneven later settlement of the pipe trench and the terrace region;

2. the PHC tubular pile has mature production process and construction process, controllable product quality and construction quality, high site construction speed and environment-friendly static pressure construction process. Although the PHC tubular pile is a soil-extruding pile and may cause adverse effects on the surrounding environment, the adverse effects can be effectively controlled as long as effective stress release measures are taken and the monitoring of the construction process on the surrounding environment is enhanced;

3. compared with a composite foundation method, the pile plate structure terrace does not need a construction mattress layer, does not require the backfilling soil compaction coefficient under the terrace plate, reduces the process links and is beneficial to saving the construction period;

4. compared with a composite foundation method, the pile distribution density of the floor of the pile-plate structure is greatly reduced, the pile number is 1/6-1/9 of the composite foundation method, the total pile length is 1/4-1/6 of the composite foundation method, the construction cost of the mattress layer is saved, and although the thickness and the arrangement of the floor are increased, and the cost of PHC tubular pile construction measures is increased, the comprehensive cost is still reduced by more than 15 percent compared with the composite foundation method;

5. the exhibition hall terrace is comparatively complicated in design because of the existence of synthesizing the trench, and the general opinion pile plate structure cost is high, makes the application of this technique receive the restriction. The invention provides a complete method for manufacturing a large-scale exhibition hall pile plate structure terrace, fills up the blank of the related technology, and proves that the invention has the effects of reducing the comprehensive manufacturing cost and saving the construction period through practical application.

Drawings

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

FIG. 2 is a cross-sectional view of a floor with a pile plate structure according to an embodiment of the invention;

FIG. 3 is a schematic view of a pile top structure of a terrace pile according to an embodiment of the present invention;

FIG. 4 is a schematic view of the arrangement of the terrace pile at the position of the integrated pipe trench (main pipe trench) according to the embodiment of the invention;

fig. 5 is a schematic layout view of a terrace pile in a comprehensive pipe trench (a communication trench and a secondary pipe trench) according to an embodiment of the invention.

Description of the labeling: 1. an auxiliary room; 2. exhibition halls; 3. a terrace; 4. a comprehensive pipe trench; 41. a base plate; 42. a side plate; 43. supporting the steel beam; 44. a pipe trench cover plate; 5. soft soil foundation; 6. terrace piles; 61. concrete pipe piles; 62. pouring a core reinforcement cage; 63. filling the main reinforcement of the reinforcement cage; 64. concrete; 7. pile caps; 71. pile cap main reinforcement; 72. a first cushion layer; 73. a brick molding bed; 8. a floor slab; 81. main ribs of the floor slab; 82. concrete for floor slab; 9. backfilling; 10. a second cushion layer; 11. and (5) building a surface layer.

Detailed Description

The concrete embodiment of the terrace with the pile plate structure of the large exhibition hall in the soft soil area is further explained with reference to fig. 1 to 5.

As shown in figure 1, the large international convention and exhibition project is located in a soft soil area, the ground surface is saturated mucky soil, and the depth of the soft soil is 10-15 meters. Exhibition hall length 378 meters, wide 90 meters, high 27 meters, the south north side is room 1 for the assistance, and the middle part is individual layer large tracts of land exhibition room 2, and exhibition room ground elevation is yellow sea elevation 6.700m, than the original ground elevation 5.500m of project high 1.2m, and exhibition room service load requires 3kPa, and exhibition room has arranged the comprehensive pipe ditch 4 that width, depth differ below ground.

In the preferred embodiment, if a composite foundation method is adopted for reinforcing a soft soil foundation in a large exhibition hall, 19961 cement mixing piles need to be arranged, the distance between foundation piles and piles is 1.2 meters, the length of the pile is 15 meters, the construction period is 70 days, a geogrid and a mattress layer need to be arranged on the top of the pile, and the compaction coefficient of the mattress layer needs to be 0.97. In addition, the terrace 3 area is a filling loading area, the comprehensive pipe trench 4 area is an excavating unloading area, if a composite foundation method is adopted to reinforce the soft soil foundation, the settlement of the terrace 3 area can be completed in several years under the additional loading action of filling and a terrace layer, the settlement is large, and the large settlement difference exists between the terrace 3 area and the comprehensive pipe trench 4 area. In order to reduce the later settlement value and the settlement difference of the floor 3 area of the exhibition hall 2 and the comprehensive pipe trench 4 area, reduce the construction difficulty, reduce the manufacturing cost and save the construction period, the pile plate structure floor is adopted.

As shown in fig. 2 and 3, a terrace pile 6 is driven into a soft soil foundation 5, the terrace pile 6 goes deep into a lower lying support layer, a pile cap 7 is arranged on the terrace pile 6, and a rigid terrace plate 8 is directly laid on the pile cap 7.

In the preferred embodiment, the terrace pile 6 is a PHC pretensioned prestressed concrete pipe pile 61 with a specification of PHC 400A 95-31/33 (namely, the diameter is 400, the wall thickness is 95, the A type pile is a 31 m pile, the lengths of the 1 st to 3 th piles from top to bottom are respectively 11m, 11m and 9m, the length of the 33m pile is 11m, 11m and 11m, and the length of the 1 st to 3 th piles from top to bottom is respectively 11m, 11m and 11m, and the a type open section steel pile tip), and is arranged uniformly in two directions, the basic pile distance is 3.5m, the local pile distance is 3m and 3.75m, and the total pile number is 2149.

In the preferred embodiment, the terrace pile 6 is vertically driven into the soft soil foundation 5.

This embodiment is preferred, terrace pile 6, according to the design of end-bearing type stake, the stake end holding power layer is 6 layers of powder clay, the stake end gets into holding power layer and is not less than 1.0m, the vertical resistance to compression bearing capacity eigenvalue of design single pile is 600 kN.

Preferably, terrace pile 6, pile bolck embedding pile cap 7, embedding degree of depth 50mm, and pile bolck 1m scope establishes irritate core steel reinforcement cage 62, adopts C40 not have shrink concrete 64 to irritate the core. The main reinforcement 63 of the core-filling reinforcement cage is 6 HRB400 hot-rolled ribbed reinforcements with the diameter of 18mm, the main reinforcement extends outwards and is bent into a horn shape, and the main reinforcement is anchored into the pile cap 7 and the rigid terrace plate 8.

In the preferred embodiment, the pile cap 7 is a 1m × 1m square reinforced concrete structure, has a thickness of 350mm, and has a bidirectional reinforcing bar at the bottom, the pile cap main bar 71 is 7 HRB400 hot-rolled ribbed bars with a diameter of 14mm, and the pile cap main bar 71 is bent and anchored into the rigid terrace plate 8;

preferably, in the embodiment, the lower part of the pile cap 7 is a first cushion layer 72, the first cushion layer 72 is a 50mm thick C15 plain concrete cushion layer, the lower part of the first cushion layer 72 is compacted backfill soil 9 through rolling compaction, and the periphery of the pile cap 7 is provided with a half-brick thick brick moulding bed 73;

in this embodiment, preferably, the rigid floor slab 8 is a reinforced concrete slab, the slab thickness is 250mm, the local slab span is large, the slab thickness of the overhanging region is 300mm, the two-layer bidirectional reinforcement is arranged in the slab, the main reinforcement 81 of the floor slab is an HRB400 hot-rolled ribbed reinforcement with the diameter of 14mm, and the reinforcement interval is 150 mm;

in the preferred embodiment, the lower part of the rigid terrace plate 8 is a second cushion layer 10, the second cushion layer 10 is a plain concrete cushion layer with the thickness of 100mm, the lower part of the second cushion layer 10 is backfill soil 9 compacted by rolling, and the compaction degree meets the walking and working requirements of the pile pressing equipment of the terrace pile 6;

preferably, in this embodiment, the rigid floor slab concrete 82 is labeled C40, and is poured simultaneously with the pile cap 7;

in the preferred embodiment, the upper part of the rigid floor slab 8 is a building surface layer 11 with a thickness of 100mm, and is a 94-thick C30 leveling layer + 6-thick polyurethane mortar self-leveling floor.

As shown in fig. 1, 4 and 5, in the area of the integrated pipe trench 4, the arrangement of the terrace piles 6 is locally adjusted to meet the requirement of the bearing capacity of the integrated pipe trench 4.

In the preferred embodiment, the integrated pipe trench 4 is a U-shaped reinforced concrete structure, and includes a bottom plate 41 and side plates 42, the side plates 42 are connected to the rigid floor 8 of the exhibition hall 2, and the upper part of the pipe trench is provided with a support steel beam 43 and a polymer pipe trench cover plate 44.

In the present embodiment, the cross-sectional dimensions (width × depth) of the integrated pipe trench 4 are 3.3 × 3.7m (main pipe trench), 2.1 × 2.35m (communication trench), and 1.3 × 1.4m (communication trench), respectively.

This embodiment is preferred, when synthesizing trench 4 for the main pipe ditch of width 3.3m, arranges terrace pile 6 under trench both sides curb

plate

42, 6 specifications of terrace pile are the same with exhibition room terrace 3 region, and pile cap 7 is cancelled at the pile top, and direct embedding trench bottom plate 50mm, the core way is irritated at the pile top is with picture 3, and the trench bottom plate 41 is directly anchored to irritate core steel reinforcement cage owner muscle 71.

In the preferred embodiment, when the integrated pipe trench 4 is a communication trench with a width of 2.1m and a secondary pipe trench with a width of 1.3m, the floor pile 6 is arranged at the center of the bottom plate 41 of the pipe trench, the specification of the floor pile 6 is the same as that of the floor 3 area of the exhibition hall, and the pile cap 7 is arranged on the pile top, and the method is the same as that of fig. 3.

The invention effectively solves the problems of large later settlement value and large settlement difference between the terrace 3 area and the comprehensive pipe trench 4 area by utilizing the characteristics of high bearing capacity and small settlement of the terrace pile 6; because the contribution of the soil between piles to the bearing capacity of the ground is not considered during the structure calculation, the problems of high backfill compaction requirement and high quality control difficulty of the backfill soil 9 of a large-area exhibition hall are solved, and the construction difficulty is reduced; the pile construction process is mature, and the construction quality is easier to control; compared with a composite foundation, the number of the terrace piles 6 is far smaller than that of the foundation piles of the composite foundation, the total pile length is greatly reduced, the investment of a mattress layer and a geogrid is saved, and the effects of reducing the comprehensive manufacturing cost by more than 15% and saving the construction period by more than 30 days are achieved.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. The utility model provides a large-scale exhibition hall pile slab structure terrace in soft soil area, its characterized in that: the pile is characterized by comprising a terrace pile driven into a soft soil foundation, wherein a pile cap is arranged on the terrace pile, a ground plate is paved on the pile cap, and the terrace pile, the pile cap and the ground plate are anchored through steel bars to form an integral stress structure.

2. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 1, characterized in that: the terrace piles are PHC pretensioned prestressed concrete pipe piles which are evenly arranged in two directions and vertically driven into the soft soil foundation.

3. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 2, characterized in that: the terrace pile is a friction pile or an end-bearing pile.

4. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 1, characterized in that: the pile bottom of the terrace pile is provided with an opening type pile tip, the pile top is embedded into the pile cap by 50-100mm, the pile top is subjected to core filling treatment within the range of 1-2m, and the main reinforcement of the core filling reinforcement cage extends outwards and is anchored into the pile cap and the terrace plate.

5. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 1, characterized in that: the pile cap is of a square reinforced concrete structure, the bottom of the pile cap is provided with bidirectional reinforcing bars, and the main reinforcing bars are bent and upwards turned and anchored into the floor slab.

6. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 5, characterized in that: the lower part of the pile cap is provided with a first cushion layer which is 50-100mm thick plain concrete, the lower part of the first cushion layer is backfilled soil compacted by rolling, and the periphery of the pile cap is provided with a brick moulding bed.

7. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 1, characterized in that: the floor slab is a reinforced concrete slab, the economic slab is 200-300 mm thick, and double-layer bidirectional reinforcing bars are arranged in the slab.

8. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 1, characterized in that: and the lower part of the rigid terrace plate is provided with a second cushion layer, the second cushion layer is a plain concrete cushion layer with the thickness of 100mm, and the lower part of the second cushion layer is backfilled soil compacted by rolling.

9. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 1, characterized in that: at the comprehensive pipe ditch part, the terrace piles are arranged below side plates on two sides of the pipe ditch or arranged at the central position of a bottom plate of the pipe ditch.

10. The terrace of the pile plate structure of the large-scale exhibition hall in the soft soil area of claim 9, characterized in that: when the terrace pile is arranged under the lateral walls of the two sides of the pipe ditch, the cap pile and the pile top core-pouring steel reinforcement cage main reinforcement are directly anchored into the bottom plate of the pipe ditch.