CN108330963A - A kind of constructing device for inside soil body existing pile foundation pile extension - Google Patents

Abstract

The invention discloses a construction device for connecting existing pile foundations inside the soil body: determining the position of the existing pile foundation, the elevation of the pile top, and the height of overfilled concrete at the top of the pile; excavating the soil body by means of manual digging , and set up a brick retaining wall; excavate to the super-filled part of the existing pile foundation, remove the laitance at the super-filled part, and remove to fresh and dense concrete, and ensure that the length of the main reinforcement of the existing pile foundation meets the requirements; manual excavation The end of the hole pile is in the form of an enlarged head; the reinforcement cage at the supplementary pile is lowered and welded with the main reinforcement of the existing pile foundation; the concrete at the supplementary pile is poured and fully vibrated and compacted. The invention solves the construction problem of connecting existing pile foundations below the ground. Compared with the traditional treatment method, the invention can reduce large-area earthwork excavation, earthwork backfill and concrete pouring, and greatly forms the foundation soil. protection, safe and reliable and reduce construction costs.

Description

A construction device for connecting existing pile foundations in soil

technical field

The invention relates to a construction device for connecting piles to pile foundations, in particular to a construction device for connecting piles to existing pile foundations inside the soil.

Background technique

The pile foundation is an ancient and common foundation form. The function of the pile is to transfer the load of the superstructure to the hard and less compressible soil or rock around the pile and at the pile end by using its stiffness much greater than that of the pile, so as to reduce the Settlement, making buildings (structures) meet the requirements of normal use functions and earthquake resistance. The pile foundation is widely used because of its high bearing capacity, good stability, small settlement and differential settlement, fast settlement stability, good seismic performance, and adaptability to various complex geological conditions. In addition to being mainly used to bear vertical compressive loads in general industrial and civil buildings, pile foundations are also used in bridges, ports, highways, docks, offshore drilling platforms, towering and high reconstruction (structure) buildings, retaining structures and In seismic engineering, it is used to bear lateral wind force, wave force, earth pressure, earthquake force, vehicle braking force and other horizontal forces and vertical pullout loads. According to incomplete statistics, more than 1 million piles are used in China every year.

At present, in the construction of pile foundations, there are still many uncontrollable factors that affect the pile quality and effect of pile foundations. One of the more common situations is that the construction pile length does not meet the requirements. The reasons why the construction pile length does not meet the requirements are mainly divided into the following aspects: 1. The technical disclosure work on the construction site is not in place, and the pile length pile diameter, pile top elevation, and pile end elevation have not been clearly implemented to specific management personnel; 2. The construction site The management personnel are careless, the communication and coordination between the participating units are not in place, and the supervision personnel are not in place; 3. The construction operators do not obey the management personnel's arrangement, and proceed to the next process construction without authorization.

A typical case where the pile length does not meet the requirements is that the elevation of the pile top does not meet the design requirements, and piles need to be connected on the upper part of the pile foundation that has been constructed to meet the design elevation requirements. If this kind of situation is encountered in the project, the current traditional treatment method is to carry out large-scale earthwork excavation, excavate the foundation soil to the elevation of the pile top of the existing pile foundation, remove the overfilled concrete on the top of the pile, and then carry out Pile work.

This is feasible when the processing area and excavation depth are small, but there are many difficulties in the case of large excavation depth and wide range, which are mainly divided into the following aspects:

1. In order to reduce the ground elevation to the fixed elevation of the existing piles, a large area of earthwork excavation is required. If the excavation depth is too large, the support work for the foundation pit will be required. This will greatly increase the construction cost and greatly increase the construction cost. Uneconomical.

2. After the pile connection is completed, earthwork backfilling is required to return the ground elevation to the design elevation. This will also increase the construction cost. At the same time, earthwork backfilling in the exposed area of the pile head is quite difficult. .

3. The excavation and backfilling of the earth will seriously damage the original state of the foundation soil, greatly disturb the foundation soil, and bring many disadvantages to the stability, settlement, differential settlement and seismic performance of the building foundation in the future.

In addition, excavation and backfilling of large areas of soil will have a great impact on the construction period, and there are many other uncertain factors in the entire construction process. Massive earthwork transportation is also a great test for site management and coordination.

Contents of the invention

The purpose of the present invention is to provide a safe, reliable, technically feasible, economical and reasonable construction device for connecting existing pile foundations inside the soil, aiming at the shortcomings of the above-mentioned prior art.

The technical solution of the present invention is: a construction device for connecting existing pile foundations inside the soil, which is characterized in that it includes existing pile foundations and supplementary pile foundations arranged from bottom to top, and the existing pile foundations The top of the pile is provided with super-filled concrete; the inside of the existing pile foundation is provided with the existing main reinforcement of the pile foundation, the top surface of the existing pile foundation is the elevation surface of the pile top of the existing pile foundation, and the upper part of the main reinforcement of the existing pile foundation It is connected with super-filled concrete; the supplementary pile foundation is composed of a retaining wall arranged on the outside of the supplementary pile foundation, a pile end expansion head under the supplementary pile foundation, a supplementary pile reinforcement cage inside the supplementary pile foundation and concrete for supplementary piles The top surface of the supplementary pile foundation is the design pile top elevation surface; the retaining wall is composed of bricks, and the enlarged head of the pile end extends downwards along the supplementary pile foundation and wraps around the existing pile foundation outside; the supplementary pile The reinforcement cage is welded by the main reinforcement of the supplementary pile foundation and the stirrup of the supplementary pile foundation. The main reinforcement of the supplementary pile foundation is fixedly connected with the main reinforcement of the existing pile foundation by welding. The welding length is 30cm-50cm. The stirrup of the supplementary pile foundation The spacing is set to 0.5-1 times the spacing of the existing pile foundation stirrups, and the spacing of the stirrups at the welding part of the main reinforcement of the supplementary pile foundation is set to 0.5-0.8 times the spacing of the existing pile foundation stirrups; the existing pile foundation is located in the soil Inside, the elevation of the top of the existing pile foundation is lower than the elevation of the designed pile top; the pile diameter of the supplementary pile foundation is greater than the pile diameter of the existing pile foundation, which is 1.2-1.5 times the pile diameter of the existing pile foundation , the diameter of the enlarged head at the pile end of the supplementary pile foundation is 1.2-1.5 times the pile diameter of the supplementary pile foundation.

The present invention raises the existing pile foundation pile top elevation to the design pile top elevation by setting the supplementary pile foundation, avoids large-area excavation earthwork in order to reduce the existing pile top elevation, and reduces the excavation costs. The support work of the foundation pit, which reduces the construction cost; at the same time, the existing pile foundation and pile foundation are buried inside the soil, which has little disturbance to the foundation soil, and has great influence on the stability, settlement and differential settlement of the building foundation in the future. Compared with earthwork excavation, the influence of anti-seismic performance is much lower, and the construction period is easier to control to avoid accidents.

As a preference, the supplementary pile foundation should be excavated to 0.5-1m below the height of the pile top of the existing pile foundation.

Preferably, the wall width of the supplementary pile foundation is set to 5cm, 10cm or 15cm.

Beneficial effects: the invention discloses a construction device for connecting existing pile foundations inside the soil, which economically and reasonably realizes the pile connection work of existing pile foundations inside the soil, and can avoid large-area earth excavation and Backfilling protects the foundation soil from being disturbed to the greatest extent, ensures the stability of the foundation soil, and shortens the construction period at the same time.

Description of drawings

Fig. 1 is a construction cross-sectional schematic view of a construction device for connecting existing pile foundations inside the soil according to the present invention.

Fig. 2 is a schematic structural view of the pile foundation of the present invention.

Fig. 3 is a schematic structural view of the pile-pile retaining wall of the present invention.

In the figure: 1. Design pile top elevation, 2. Supplementary pile foundation, 3. Overfilled concrete, 4. Existing pile foundation pile top elevation, 5. Existing pile foundation, 6. Supplementary pile foundation stirrups, 7 1. The main reinforcement of the pile foundation, 8. The enlarged head of the pile end of the pile, 9. The main reinforcement of the existing pile foundation, 10. The concrete of the pile, 11. The retaining wall, 12. The reinforcement cage of the pile.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, Figure 2, and Figure 3: a construction device for connecting existing pile foundations inside the soil, including existing pile foundations 5 and supplementary pile foundations 2 arranged from bottom to top, both Pile foundation pile top overfilling concrete 3;

The existing pile foundation 5 is provided with the existing pile foundation main reinforcement 9 inside, the top surface of the existing pile foundation 5 is the existing pile foundation pile top elevation surface 4, and the existing pile foundation main reinforcement 9 top is connected with the super-filling Concrete 3 connected;

Described supplementary pile foundation 2 is made up of the retaining wall 11 that is arranged on the supplementary pile foundation outside, the pile end expansion head 8 below the supplementary pile foundation, the supplementary pile reinforcement cage 12 and the supplementary pile concrete 10 inside the supplementary pile foundation; The top surface of the pile foundation 2 is the design pile top elevation surface 1;

The retaining wall 11 is composed of bricks, and the enlarged head of the pile end extends downward along the supplementary pile foundation, and is wrapped around the outside of the existing pile foundation. The foundation stirrups 6 are formed by welding, and the main reinforcements 7 of the supplementary pile foundation are fixedly connected with the existing main reinforcements 9 of the pile foundation by welding.

The existing pile foundation 5 is located inside the soil, and the pile top elevation 4 of the existing pile foundation is lower than the design pile top elevation 1, which cannot meet the design requirements, and the existing pile foundation 5 needs to be connected with piles.

The 2 pile diameters of the supplementary pile foundation are greater than the 5 pile diameters of the existing pile foundation, and are 1.2-1.5 times of the 5 pile diameters of the existing pile foundation. The diameter of the enlarged head 8 at the end of the pile-filling pile is 1.2-1.5 times the diameter of the pile foundation 2 of the pile-filling pile.

The supplementary pile foundation 2 should be excavated to 0.5-1m below the existing pile foundation pile top elevation 4.

The main reinforcement 7 of the supplementary pile foundation needs to be welded with the existing main reinforcement 9 of the pile foundation, and the welding length is 30cm-50cm. The distance between the 6 stirrups of the supplementary pile foundation is set to 0.5-1 times the distance between the stirrups of the existing pile foundation, and the distance between the stirrups at the welding part of the main reinforcement is set to 0.5-0.8 times the distance between the stirrups of the existing pile foundation.

The width of the shown retaining wall 11 is set to 5 cm, 10 cm or 15 cm.

Claims (3)

1. a kind of constructing device for inside soil body existing pile foundation pile extension, it is characterised in that：Including from bottom to top arranging both There are pile foundation and piling pile foundation, existing pile foundation stake top to be equipped with superfilled concrete；

The existing pile foundation is internally provided with existing pile foundation main reinforcement, and the top surface of the existing pile foundation is existing pile foundation stake top absolute altitude face, Existing pile foundation main reinforcement top connects with superfilled concrete；

The piling pile foundation is by being arranged the retaining wall on the outside of piling pile foundation, the stake end enlarged footing below piling pile foundation, piling pile foundation Internal piling steel reinforcement cage and piling coagulation local soil type at；The top surface of piling pile foundation is design stake top absolute altitude face；

The retaining wall is made of brick, and stake end enlarged footing is extended downwardly along piling pile foundation, is wrapped on the outside of existing pile foundation；Institute It states piling steel reinforcement cage to be welded by piling pile foundation main reinforcement and piling pile foundation stirrup, piling pile foundation main reinforcement is logical with existing pile foundation main reinforcement It crosses and is welded and fixed connection, weld length 30cm-50cm, the piling pile foundation stirrup spacing is set as existing pile foundation stirrup spacing 0.5-1 times, piling pile foundation main reinforcement welding position stirrup spacing is set as 0.5-0.8 times of existing pile foundation stirrup spacing；

The existing pile foundation is located inside soil body, and the high face of existing pile foundation top mark is less than design stake top absolute altitude face；The piling pile foundation Stake diameter be more than the stake diameter of the existing pile foundation, be 1.2-1.5 times of existing pile foundation pile diameter, the stake end expansion of the piling pile foundation 1.2-1.5 times of the stake diameter of a diameter of piling pile foundation.

2. a kind of constructing device for inside soil body existing pile foundation pile extension according to claim 1, it is characterised in that：Institute It is existing pile foundation stake top absolute altitude or less 0.5-1m to state piling pile foundation excavation face absolute altitude.

3. a kind of constructing device for inside soil body existing pile foundation pile extension according to claim 1, it is characterised in that：It mends The retaining wall width of stake pile foundation is set as 5cm, 10cm or 15cm.