CN108487268B - Square hollow stepped reducing anti-slide pile structure and construction method - Google Patents

Abstract

The anti-slide pile structure consists of five sections from top to bottom, and comprises a first pile section (1), a second pile section (2), a third pile section (3), a fourth pile section (4) and a fifth pile section (5). The third pile body section has the longest side length and the largest cross-sectional area; and then sequentially reducing the diameter of the pile body towards the pile top and the pile bottom step by step with gradually reduced side length, wherein two adjacent sections are connected by a variable cross section. The second pile body section (2) to the fourth pile body section (4) are of a pile body hollow section (6) structure. The anti-slide pile structure has strong bending resistance, shearing resistance and shearing resistance, the cross section area of the middle section of the pile body is obviously increased, and the anti-slide pile structure has stronger anti-slide capability; the anti-slide pile structure saves building materials, reduces the cost, can save the building materials such as concrete and the like by 40 to 70 percent under the same numerical values of the compression resistance, the bending resistance and the shear resistance, and has obvious economic benefit.

Description

Square hollow stepped reducing anti-slide pile structure and construction method

Technical Field

The invention relates to a square hollow stepped variable-diameter anti-slide pile structure and a construction method, and belongs to the technical field of civil engineering pile structures.

Background

With the rapid development of scientific and technological water products in the field of civil engineering, particularly in the aspects of side slopes and foundation pits, the requirements on the skid resistance of the side slopes and the foundation pits are higher and higher, and the complexity of geological conditions is added, so that more comprehensive, stronger and higher requirements are provided for the skid resistant piles. The reinforced concrete slide-resistant pile is an effective component for stabilizing the side slope by supporting and retaining the sliding force of the sliding body.

At present, a single reinforced concrete pile with a large diameter is mainly adopted for an anti-slide pile for preventing and treating landslide, the diameter of the reinforced concrete pile is consistent from top to bottom, stress borne by the anti-slide pile in the actual working process is distributed in a parabola shape with a large middle part and a small top part and bottom part, and the stress does not accord with the stress, so that partial material waste is caused. At present, in the field of civil engineering, in order to achieve the capabilities of compression resistance, bending resistance and shear resistance, a length of an anti-slide pile is generally designed to be increased, and a diameter of the anti-slide pile is increased to improve the overall strength and the stress capability of a pile foundation, so that the method undoubtedly causes the increase of workload and the reduction of working efficiency, and particularly wastes materials to cause the great increase of engineering cost.

Therefore, the square hollow stepped variable-diameter anti-slide pile structure and the construction method are found, resources can be saved to the maximum extent on the premise of governing landslide and ensuring stability and safety of landslide, economic cost is controlled, and the square hollow stepped variable-diameter anti-slide pile structure is a problem with great engineering application value.

Disclosure of Invention

The invention aims to provide a square hollow stepped variable-diameter anti-slide pile structure and a construction method, which have the advantages of small material consumption, strong supporting capacity and short construction period, and solve the problems in the prior art.

The technical scheme of the invention is that the square hollow stepped variable-diameter anti-slide pile structure comprises five sections from top to bottom, wherein the five sections comprise a first pile section, a second pile section, a third pile section, a fourth pile section and a fifth pile section; the third pile body section has the longest side length and the largest cross-sectional area; sequentially reducing the diameter of the pile body towards the pile top and the pile bottom step by step, and connecting two adjacent sections by variable cross sections;

the cross section of the five-section pile body variable-section slide-resistant pile of the slide-resistant pile structure is rectangular.

The cross section area of the five-section pile body variable-section slide-resistant pile can be increased or decreased according to needs; the adjacent variable cross-section ratio is 1: (0.5-1.5).

The second pile body section to the fourth pile body section are of hollow structures.

The invention relates to a construction method of a square hollow step diameter-variable anti-slide pile, which comprises the following steps:

(1) measuring and setting out, and determining the setting position of each pile;

(2) before pile hole excavation, facilities for leveling construction site and intercepting, draining and ventilating the ground are required to be made; the first section of the pile hole is 20cm higher than the ground, the hole opening protecting wall is reinforced, and a well mouth is locked to prevent the collapse of the slide slope surface;

(3) defining the cross sections of five pile sections of the square hollow stepped variable-diameter anti-slide pile from top to bottom as that the first pile section is 1-1 section, the second pile section is 2-2 section, the third pile section is 3-3 section, the fourth pile section is 4-4 section and the fifth pile section is 5-5 section; excavating layer by layer from top to bottom by adopting machinery, wherein the soil excavating sequence is divided into 3 stages, the 3-3 section is the first stage of excavating, the 4-4 section is the second stage of excavating, and the 5-5 section is the third stage of excavating;

(4) excavating along the section slightly larger than 1-1 at the first stage, wherein each section is 0.5-1 m, and C20 concrete retaining walls with the thickness not smaller than 150mm are constructed as soon as possible after each section is excavated; the wall protection concrete should be poured closely to the surrounding rock; before pouring, loose stones and floating soil on the rock wall should be removed, and the protective wall at the sliding surface should be strengthened; reinforcing steel bars are added into concrete for reinforcing lining of the protecting wall and the orifice which bear larger thrust;

(5) excavating along the section slightly larger than 4-4 in the second stage, and repeating the excavation until the designed depth is reached;

(6) excavating along the section slightly larger than 5-5 in the third stage, and repeating the excavation until the designed depth is reached;

(7) recording geological sections and sliding surface positions in time during excavation construction, filling a geological histogram well, and performing support in time according to geological conditions; at the change position of the earth-rock layer and near the sliding surface, the support should be strengthened, and the protective wall is not segmented; paying attention to the supporting condition, if the supporting condition is deformed and damaged, taking a reinforcing measure immediately, and evacuating underground constructors; after the pile hole is dug to the designed elevation, supervision, design and constructors can simultaneously check the hole, and the elevation of the bottom of the hole is determined by combining the actual condition of the sliding surface;

(8) hoisting a steel reinforcement cage, removing loose stones and floating soil at the bottom of a hole before pouring concrete, draining accumulated water, and checking the size of a clearance section and the positioning condition of a steel reinforcement framework;

(9) pouring concrete to 2-2 sections; when underground water develops, an underwater concrete pouring method is adopted;

(10) maintaining and supporting a formwork;

(11) and pouring concrete to the pile top. Maintaining, removing the mould and backfilling soil.

The construction order of the method of the invention is as follows: paying off → artificially digging hole 1 st mould → pouring concrete dado → dado demolition → artificially digging hole 2 nd mould → pouring concrete dado → repeating the digging to the designed depth → putting in reinforcement cage → ground water treatment → pouring pile concrete to 2-2 section → maintenance → formwork → pouring pile concrete to pile top → maintenance → demolition → backfill soil.

The anti-slide pile structure has the beneficial effects that the anti-slide pile structure has extremely strong bending resistance, shearing resistance and shearing resistance, the cross section area of the middle section of the pile body is obviously increased, and the anti-slide pile structure has stronger anti-slide capability; the anti-slide pile structure saves building materials, reduces the cost, can save the building materials such as concrete and the like by 40 to 70 percent under the same numerical values of the compression resistance, the bending resistance and the shear resistance, and has obvious economic benefit. The length and the size of the middle section of the anti-slide pile body can be correspondingly adjusted according to the design requirements and the geological conditions, the applicability is strong, the construction period is shortened, and the social benefit is obvious.

Drawings

FIG. 1 is a front view of the square hollow stepped variable diameter slide-resistant pile structure of the present invention;

FIG. 2 is a side view of the square hollow stepped variable diameter slide-resistant pile structure of the present invention;

FIG. 3 is an enlarged plan view of the square hollow stepped variable-diameter slide-resistant pile structure according to the present invention;

FIG. 4 is a schematic design diagram of the square hollow stepped variable diameter slide-resistant pile structure of the present invention;

FIG. 5 is a schematic cross-sectional view of the square hollow stepped diameter-variable anti-slide pile of the present invention in landslide control;

FIG. 6 is a three-dimensional schematic view of the square hollow stepped variable-diameter anti-slide pile in landslide control according to the present invention;

in the figure, 1 is a first pile section, 2 is a second pile section, 3 is a third pile section, 4 is a fourth pile section, 5 is a fifth pile section, 6 is a pile body hollow section, 7 is a stressed steel bar, 8 is a stirrup, 9 is a bending moment curve, 10 is a bending moment envelope curve, 11 is a sliding body, and 12 is a sliding surface.

Detailed Description

The detailed description of the invention is shown in the drawings.

As shown in fig. 1, fig. 2, and fig. 3, the square hollow stepped diameter-variable slide-resistant pile structure of the present embodiment is composed of five sections, which are a first pile section 1, a second pile section 2, a third pile section 3, a fourth pile section 4, and a fifth pile section 5. Wherein the first pile section 1 and the fifth pile section 5 are solid structures; the first, third and fourth pile body sections 2, 3, 4 are hollow.

Five sections of hollow ladder reducing slide-resistant pile body cross-sections are rectangle in this embodiment, and adjacent variable cross-section ratio is 1: (0.5-1.5), the length of the five sections of the variable cross-section slide-resistant piles can be increased or shortened according to the actual situation of the project.

As a further improvement, the length and width of the variable-section pile and the length and width of the hollow section can be increased or decreased on the basis according to geological conditions. The pile length of the variable cross-section pile can be increased or shortened on the basis of the pile according to geological conditions so as to increase the stability and the economy.

The construction method of the square hollow stepped reducing slide-resistant pile structure comprises the following steps:

(1) and (5) measuring and setting out, and determining the setting position of each pile.

(2) Before the pile hole is excavated, facilities for leveling a construction site and cutting, draining and ventilating the ground are required to be manufactured, the first section of the pile hole is required to be 20cm higher than the ground, an orifice retaining wall is reinforced, a wellhead locking port is required to be manufactured, and collapse of a landslide surface is prevented.

(3) The cross sections of five pile sections of the square hollow stepped variable-diameter anti-slide pile are defined from top to bottom, wherein the first pile section is 1-1 section, the second pile section is 2-2 section, the third pile section is 3-3 section, the fourth pile section is 4-4 section, and the fifth pile section is 5-5 section.

Excavating layer by layer from top to bottom by adopting machinery, wherein the soil excavating sequence is divided into 3 stages, the 3-3 section is the first stage of excavating, the 4-4 section is the second stage of excavating, and the 5-5 section is the third stage of excavating.

(4) And in the first stage, excavating along the section slightly larger than 1-1, wherein each excavation is a section with the length of 0.5-1 m, and constructing the C20 concrete retaining wall with the thickness not smaller than 150mm as soon as possible after each excavation. The wall protection concrete should be poured closely to the surrounding rock; before pouring, loose stones and floating soil on the rock wall should be removed, and the protective wall at the sliding surface should be strengthened. Reinforcing steel bars are added to the concrete of the protective wall bearing larger thrust and the reinforced lining of the orifice.

(5) And excavating along the section slightly larger than 4-4 in the second stage, and repeating the excavation until the designed depth is reached.

(6) And excavating along the section slightly larger than 5-5 in the third stage, and repeating the excavation until the designed depth is reached.

(7) And (3) recording the positions of a geological section and a sliding surface in time during excavation construction, filling a geological column diagram well, and performing support in time according to geological conditions. The support should be strengthened at the change position of the earth-rock layer and near the sliding surface, and the protective wall is not segmented. And (4) paying attention to the supporting condition, if the support is deformed and damaged, taking a reinforcing measure immediately, and evacuating underground constructors. After the pile hole is dug to the designed elevation, supervision, design and constructors can simultaneously check the hole, and the elevation of the bottom of the hole is determined by combining the actual condition of the sliding surface.

(8) Hoisting a steel reinforcement cage, removing loose stones and floating soil at the bottom of the hole before pouring concrete, draining accumulated water, and checking the size of a clearance section and the positioning condition of a steel reinforcement framework.

(9) And pouring concrete to 2-2 sections. Adopting pump sending concrete to pour the friction pile, pouring in-process every continuous pouring 0.5 ~ 0.8m, adopting plug-in vibrator to smash closely knit 1 time, plug-in vibrator cluster section of thick bamboo or pipe end opening and concrete face of pouring distance should be controlled between 1.0 ~ 2 m. If the underground water is developed, an underwater concrete pouring method is adopted.

(10) And (5) maintaining and supporting the formwork.

(11) And pouring concrete to the pile top. Maintaining, removing the mould and backfilling soil.

Claims (1)

1. The construction method of the square hollow stepped variable-diameter anti-slide pile is characterized in that the anti-slide pile structure consists of five sections from top to bottom, and the anti-slide pile structure comprises a first pile body section, a second pile body section, a third pile body section, a fourth pile body section and a fifth pile body section; the third pile body section has the longest side length and the largest cross-sectional area; sequentially reducing the diameter of the pile body towards the pile top and the pile bottom step by step, and connecting two adjacent sections by variable cross sections;

the cross sections of the five-section pile body variable-section slide-resistant piles of the slide-resistant pile structure are all rectangular;

the cross section area of the five-section pile body variable-section slide-resistant pile can be increased or decreased according to needs; the adjacent variable cross-section ratio is 1: (0.5-1.5);

the second pile body section to the fourth pile body section are of hollow structures;

the construction method of the square hollow stepped variable-diameter slide-resistant pile comprises the following steps:

(1) measuring and setting out, and determining the setting position of each pile;

(2) before pile hole excavation, facilities for leveling construction site and intercepting, draining and ventilating the ground are required to be made; the first section of the pile hole is 20cm higher than the ground, the hole opening protecting wall is reinforced, and a well mouth is locked to prevent the collapse of the slide slope surface;

(3) defining the cross sections of five pile sections of the square hollow stepped variable-diameter anti-slide pile from top to bottom as that the first pile section is 1-1 section, the second pile section is 2-2 section, the third pile section is 3-3 section, the fourth pile section is 4-4 section and the fifth pile section is 5-5 section; excavating layer by layer from top to bottom by adopting machinery, wherein the soil excavating sequence is divided into 3 stages, the 3-3 section is the first stage of excavating, the 4-4 section is the second stage of excavating, and the 5-5 section is the third stage of excavating;

(4) excavating along the section slightly larger than 3-3 at the first stage, wherein each section is 0.5-1 m, and C20 concrete retaining walls with the thickness not smaller than 150mm are constructed as soon as possible after each section is excavated; the wall protection concrete should be poured closely to the surrounding rock; before pouring, loose stones and floating soil on the rock wall should be removed, and the protective wall at the sliding surface should be strengthened; reinforcing steel bars are added into concrete for reinforcing lining of the protecting wall and the orifice which bear larger thrust;

(5) excavating along the section slightly larger than 4-4 in the second stage, and repeating the steps to reach the designed depth;

(6) excavating along the section slightly larger than 5-5 in the third stage, and repeating the steps to reach the designed depth;

(7) recording geological sections and sliding surface positions in time during excavation construction, filling a geological histogram well, and performing support in time according to geological conditions; at the change position of the earth-rock layer and near the sliding surface, the support should be strengthened, and the protective wall is not segmented; paying attention to the supporting condition, if the supporting condition is deformed and damaged, taking a reinforcing measure immediately, and evacuating underground constructors; after the pile hole is dug to the designed elevation, supervision, design and constructors can simultaneously check the hole, and the elevation of the bottom of the hole is determined by combining the actual condition of the sliding surface;

(8) hoisting a steel reinforcement cage, removing loose stones and floating soil at the bottom of a hole before pouring concrete, draining accumulated water, and checking the size of a clearance section and the positioning condition of a steel reinforcement framework;

(9) pouring concrete to 2-2 sections; when underground water develops, an underwater concrete pouring method is adopted;

(10) maintaining and supporting a formwork;

(11) pouring concrete to the pile top, maintaining, removing the mould and backfilling.