Pre-drilling tubular pile foundation

Abstract

The utility model belongs to the technical field of building construction, and provides a pre-drilling tubular pile foundation which comprises a pile hole, clay, a tubular pile and a reinforcement cage, and the pile hole is formed in a target rock stratum; the clay is filled in the pile hole; a pile tip is arranged on the lower portion of the pipe pile, the pipe pile is pressed in the pile hole, the pipe pile extrudes the clay, and a gap between the pipe pile and the pile hole is filled with the clay; the reinforcement cage is arranged in the pipe pile, the pipe pile is filled with concrete, and the upper portion of the reinforcement cage is exposed out of the pipe pile. The pre-drilling tubular pile foundation is reasonable in structure and good in economical efficiency, and the problems that the foundation treatment cost of a strong karst cave development area and even a karst cave subsidence area is uncontrollable, and the construction time is long are solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of building construction, especially relates to a pre-drilling pipe pile foundation. BACKGROUND

[0002] China is vast in territory, and karst cave, such as complex geological conditions, also has extensive distribution in Guangdong, Guangxi, Guizhou, Chongqing and other places.The management of cave is also a difficult problem that engineering personnel often encounter.At present, the common cave management mode in the area with strong development of karst cave is:

[0003] First, grouting reinforcement:

[0004] 1. drilling in advance in the foundation, the hole diameter and hole distance are determined according to the foundation condition and design requirement;

[0005] 2. grouting material is injected into the hole through the pressure pump until the grouting material fills the hole;

[0006] 3. after the grouting material is filled, continue grouting, gradually improve the grouting pressure until the design requirement is reached;

[0007] 4. the same operation is carried out for each hole to ensure uniform distribution of grouting material.

[0008] In the area with strong development of karst and good connectivity of cave, the engineering quantity is difficult to estimate, the cost is huge, and the construction period is long.

[0009] Second, full casing rotary drilling cast-in-place pile:

[0010] 1. select appropriate steel casing according to the hole size, and hit the steel casing into the ground section by section.

[0011] 2. hole digging and pouring: use rotary drilling machine to dig hole.

[0012] 3. put the reinforcement cage into the hole, then pour concrete into the hole to form the pile body.

[0013] 4. vibration treatment: after pouring concrete, use the vibrator for vibration treatment to improve the compactness of concrete and the quality of pile body.

[0014] 5. curing treatment: after completing the pile body pouring, carry out appropriate curing treatment to ensure the strength development and stability of the pile body.

[0015] This kind of pile type must use steel casing for the whole length, which is very costly and has a long construction period.

[0016] Therefore, in order to overcome the problems of high cost and long construction period in the existing cave management area, a pre-drilling pipe pile foundation is provided to solve the above problems. UTILITY MODEL CONTENTS

[0017] To solve the above technical problems, the utility model provides a pre -drilling pipe pile foundation, include:

[0018] Pile hole, the pile hole is shaped in target rock stratum;

[0019] Clay, the clay is filled in the pile hole;

[0020] Pipe pile, the lower part of the pipe pile is provided with pile tip, the pipe pile is pressed in the pile hole, the pipe pile extrudes the clay, the gap between the pipe pile and the pile hole is filled by the clay;

[0021] Steel reinforcement cage, the steel reinforcement cage is placed in the pipe pile, the pipe pile is filled with concrete, the upper part of the steel reinforcement cage is exposed to the pipe pile.

[0022] Optionally, the diameter of the pile hole is 100-200mm larger than the diameter of the pipe pile.

[0023] Optionally, the steel reinforcement cage includes a support plate, stirrups, a pile top cross steel reinforcement and longitudinal reinforcement, the support plate is tightly installed in the pipe pile, the pile top cross steel reinforcement is located at the upper end of the pipe pile, a plurality of stirrups and a plurality of longitudinal reinforcement are arranged between the support plate and the pile top cross steel reinforcement to form a cage body, the lower end of the longitudinal reinforcement is connected to the support plate, and the upper end of the longitudinal reinforcement is connected to the pile top cross steel reinforcement and extends to the outside of the pile top cross steel reinforcement.

[0024] Optionally, the concrete is micro-expansion concrete.

[0025] Optionally, the pile hole is a pre-drilled pile hole.

[0026] Optionally, the pipe pile is a high-strength prestressed pipe pile.

[0027] Optionally, the pile tip is a closed pile tip, which guides the pile body of the pipe pile into the soil layer and isolates water and soil from entering the pipe pile.

[0028] Compared with the prior art, the utility model has the beneficial effects that:

[0029] The pre-drilling pipe pile foundation provided by the utility model includes a pile hole, clay, a pipe pile and a steel reinforcement cage, the pile hole is shaped in target rock stratum; the clay is filled in the pile hole; the lower part of the pipe pile is provided with a pile tip, the pipe pile is pressed in the pile hole, the pipe pile extrudes the clay, and the gap between the pipe pile and the pile hole is filled by the clay; the steel reinforcement cage is placed in the pipe pile, the pipe pile is filled with concrete, and the upper part of the steel reinforcement cage is exposed to the pipe pile. The pre-drilling pipe pile foundation has reasonable structure and good economy, and helps to solve the problems of uncontrollable foundation treatment cost and long construction time in a strong development area of karst cave or even a karst cave collapse area. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is the overall layout schematic diagram of the pre-drilled pipe pile foundation of the utility model.

[0031] Illustration:

[0032] 1, pile hole; 2, clay; 3, pipe pile; 4, pile tip; 5, concrete; 6, supporting plate; 7, stirrup;

[0033] 8, pile top cross steel bar; 9, longitudinal reinforcement. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the utility model more clear and understandable, the utility model will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0035] In the description of the utility model, it should be pointed out that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as limiting the utility model.

[0036] In addition, in the description of the utility model, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection, it can be mechanical connection, or electrical connection, it can be directly connected, or indirectly connected through intermediate medium, it can also be the communication between two elements, it can be wireless connection, or wired connection. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0037] In addition, the technical features involved in the different embodiments of the utility model described subsequently can be combined with each other as long as there is no conflict between them.

[0038] For example, Figure 1The utility model discloses an embodiment provides a kind of pre-drilled hole pipe pile 3 foundation, including pile hole 1, clay 2, pipe pile 3 and reinforcement cage, pile hole 1 is shaped in target rock layer;Clay 2 is filled in pile hole 1;The lower part of pipe pile 3 is provided with pile tip 4, pipe pile 3 is pressed into pile hole 1, pipe pile 3 extrudes clay 2, and the gap between pipe pile 3 and pile hole 1 is filled by clay 2;Reinforcement cage is placed in pipe pile 3, and pipe pile 3 is filled with concrete 5, and the upper part of reinforcement cage is exposed to pipe pile 3.Pre-drilled hole pipe pile 3 foundation structure is reasonable, pipe pile 3 and reinforcement cage can be prefabricated outside the field, and it is better in economy, construction period is shorter, help to solve the problem of uncontrolled foundation treatment cost in strong development area of karst cave even karst collapse area, and long construction time.

[0039] Specifically, in the embodiment, in order to better manage the karst cave, the pile hole 1 can be drilled at a predetermined position by a pile machine, so that the pile hole 1 is pre-drilled and shaped in the target rock layer. The pile hole 1 of the embodiment is not limited to be used only for karst cave management, but can also be applied to pile foundations for various construction. The operation of drilling the pile hole 1 by the pile machine is a general technique and will not be described here. Preferably, in order to allow the pipe pile 3 to be smoothly pressed into the bearing layer, the diameter D1 of the pile hole 1 is generally 100-200 mm larger than the diameter D2 of the pipe pile 3, and the gap C between the inner hole wall of the pile hole 1 and the outer pipe wall of the pipe pile 3 is generally 50-100 mm.

[0040] Further, in the embodiment, after the construction of the pile hole 1 is completed, a certain amount of loose clay 2 is first filled in the pile hole 1. The amount of clay 2 filled is determined based on the gap between the pile hole 1 and the pipe pile 3. In the embodiment, the clay 2 filled in the pile hole 1 serves two purposes. First, it supports the pipe pile 3 so that the pipe pile 3 does not sink too fast during pressing and provides convenience for pile pressing. Second, it fills the gap between the pipe pile 3 and the pre-drilled hole wall, allowing the pipe pile 3 to better perform its load-bearing function.

[0041] Further, in the embodiment, the pipe pile 3 is a high-strength prestressed pipe pile 3, which is the main component for bearing. The lower part of the pipe pile 3 is provided with a pile tip 4, and the pipe pile 3 is pressed into the pile hole 1, extruding the clay 2, and the gap between the pipe pile 3 and the pile hole 1 is filled with clay 2. In the embodiment, the pile tip 4 is a closed-type pile tip 4. First, the pile tip 4 can protect the pile end from being damaged during soil penetration and guide the pile body into the soil layer, which helps to control the verticality, reduces the probability of broken piles, and increases the penetration ability of the pile to the soil layer. Second, the closed-type pile tip 4 can effectively prevent corrosive water or soil from flowing into the inner cavity of the pipe pile 3, thereby improving the durability of the pipe pile 3.

[0042] Further, in the embodiment, the reinforcement cage is preferably a prefabricated reinforcement cage, the reinforcement cage is placed in the pipe pile 3, the pipe pile 3 is filled with the concrete 5, and the upper part of the reinforcement cage is exposed outside the pipe pile 3. More specifically, the concrete 5 is micro-expansive concrete 5, which firstly increases the lateral stiffness of the pipe pile 3, and secondly increases the self weight of the pipe pile 3, which is beneficial to resisting floating. The reinforcement cage comprises a bearing plate 6, a stirrup 7, a pile top cross steel 8 and a longitudinal reinforcement 9, the bearing plate 6 is tightly installed in the pipe pile 3, and the pile top cross steel 8 is located at the upper end of the pipe pile 3; a plurality of stirrups 7 and a plurality of longitudinal reinforcements 9 are arranged between the bearing plate 6 and the pile top cross steel 8 to form a cage body, the lower end of the longitudinal reinforcement 9 is connected to the bearing plate 6, and the upper end of the longitudinal reinforcement 9 is connected to the pile top cross steel 8 and extends outward from the pile top cross steel 8. The function of the reinforcement cage is to make the connection between the pile foundation and the upper structure more firm, so as to better cooperate.

[0043] The pre-drilled pipe pile 3 foundation of the embodiment is implemented as follows: firstly, a pile hole 1 is pre-drilled by a machine, then clay 2 is filled into the hole, then a high-strength prestressed pipe pile 3 is pressed into the hole, and micro-expansive concrete 5 is poured into the pile core of the pipe pile 3. When the concrete 5 in the pile core reaches the bearing plate 6, the reinforcement cage is placed, and the pouring of the concrete 5 is continued until the top of the pile, and the pre-drilled pipe pile 3 foundation of the embodiment has the advantages that when used in a strong karst development area or even a karst collapse area, the investment is controllable, the cost of the foundation is reduced by 1 / 3-1 / 2 compared with a steel casing cast-in-place pile foundation, and the construction period of the high-strength prestressed pipe pile 3 foundation is short.

[0044] The above embodiment is only a preferred embodiment of the utility model, and cannot be used to limit the range of protection of the utility model, and any non-substantial change and replacement made by a person skilled in the art on the basis of the utility model belongs to the range of protection required by the utility model.

Claims

1. A pre-bored pipe pile foundation, characterized by, The invention relates to a pile hole, a clay filled in the pile hole, a pipe pile with a pile tip, a reinforcement cage, and a concrete filled in the pipe pile. The diameter of the pile hole is 100-200mm larger than the diameter of the pipe pile. The reinforcement cage comprises a base plate, a stirrup, a pile top cross steel bar, and a longitudinal steel bar. The concrete is micro-expansion concrete. The pile hole is a pre-drilled pile hole.

2. The pre-drilled pipe pile foundation of claim 1, wherein, The pipe pile is a high-strength prestressed pipe pile.

3. The pre-bored pipe pile foundation according to claim 1, wherein, The pile tip is a closed pile tip which guides the pile body of the pipe pile into the soil and separates water and soil from entering the pipe pile.

4. The pre-bored pipe pile foundation of claim 1, wherein, ​ 5. The pre-bored pipe pile foundation according to claim 1, wherein, ​ 6. The pre-drilled pipe pile foundation of claim 1, wherein, ​ 7. The pre-bored pipe pile foundation of claim 1, wherein, ​

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