CN212358276U

CN212358276U - Grouting type steel underpinning piles for underground layers

Info

Publication number: CN212358276U
Application number: CN201921757168.1U
Authority: CN
Inventors: 侯迪; 赵新媛; 孙添娇; 蒋宗南; 李亚洲
Original assignee: Shandong University of Science and Technology
Current assignee: Shandong University of Science and Technology
Priority date: 2019-10-19
Filing date: 2019-10-19
Publication date: 2021-01-15
Anticipated expiration: 2029-10-19

Abstract

The utility model discloses a slip casting formula shaped steel underpins stake for underground increases layer belongs to basic underpinning technical field, for solving the crowded soil effect that static pressure stake produced when the soil body impresses big, the bearing capacity is not enough, the problem design that recycle is worth lowly. The utility model consists of a pile body, a pile head, a pile tip, an anchor bar hole and a grout overflow hole; the pile body is hollow, slurry overflow holes are distributed on the periphery of the pile body, the pile body is formed by welding three H-shaped steels, and the cross section of the pile body is shaped as follows: the middle part is a regular triangle, and three T-shaped flanges are distributed on the periphery of the middle part; the section of the pile head is the same as that of the pile body, and anchor bar holes are distributed on each flange web; the section of the upper end of the pile tip is the same as that of the pile body, the lower end of the pile tip is a triangular cone welded by triangular steel plates, and the periphery of the pile tip is provided with a grout overflow hole; the anchor bar holes are round holes, and the number and the size of the anchor bar holes are determined by the number and the thickness of steel bars needing to be anchored in the engineering; the slurry overflow hole is a circular hole with the diameter of 2 cm, and a round shell-shaped soil blocking cover is welded on the slurry overflow hole. The utility model discloses simple structure, engineering practicality are strong.

Description

Grouting type profile steel underpinning pile for underground layer-adding

Technical Field

The utility model belongs to the technical field of the basis underpins, concretely relates to underpins stake, especially relates to a slip casting formula shaped steel underpins stake for underground layer increase.

Background

With the continuous development of cities, underground spaces of cities are continuously developed and utilized, and underground layer-adding of existing buildings is an effective means for enlarging the use area and increasing the use functions of the existing buildings. The foundation underpinning technology is a key technology involved in underground storey-adding engineering, and because construction sites are often narrow, static pressure piles are mostly adopted in the engineering to underpin the original foundation. The conventional static pressure pile is of a type of a prefabricated reinforced concrete pile and a steel pipe pile, which have some disadvantages although having a simple structure: due to the fact that the cross section area is generally large, a large soil squeezing effect can be caused in the pile pressing process; because the side surface of the pile is smooth, the effective pile side resistance cannot be generated, and the bearing capacity is low; because the pile body is cast by reinforced concrete, the value of recycling the pile body after pile cutting is not high, and the engineering cost is increased. In order to solve the problems, a large amount of data search, field research and related experiments are conducted to research, and a grouting type profile steel underpinning pile for underground layer adding is invented, has small soil extrusion effect, high bearing capacity and higher recycling value in the pile pressing process, and effectively solves the problems in the construction process of the traditional pile.

Disclosure of Invention

The utility model aims at providing a slip casting formula shaped steel underpins stake for underground increases layer, this underpins stake crowded soil effect that produces at the pile pressing in-process is little, bearing capacity is high, have higher recycle value, simple structure, and technical economy is feasible, and the engineering practicality is strong.

The utility model adopts the technical proposal that: a grouting type profile steel underpinning pile for underground added layers is composed of a pile body, a pile head, a pile tip, an anchor bar hole and a grout overflow hole; the pile body is hollow, slurry overflow holes are distributed on the periphery of the pile body, the pile body is formed by welding three H-shaped steels, and the cross section of the pile body is shaped as follows: the middle part is a regular triangle, and three T-shaped flanges are distributed on the periphery of the middle part; the section of the pile head is the same as that of the pile body, and anchor bar holes are distributed on each flange web; the section of the upper end of the pile tip is the same as that of the pile body, the lower end of the pile tip is a triangular cone welded by triangular steel plates, and the periphery of the pile tip is provided with a grout overflow hole; the anchor bar holes are round holes, and the number and the size of the anchor bar holes are determined by the number and the thickness of steel bars needing to be anchored in the engineering; the slurry overflow hole is a circular hole with the diameter of 2 cm, and a round shell-shaped soil blocking cover is welded on the slurry overflow hole.

The utility model discloses a construction application method is: a grouting type profile steel underpinning pile for underground storey addition is characterized in that during construction, a pile body, a pile head and a pile tip which are prefabricated in a factory are transported to a construction position, the upper end of the pile tip is welded with the lower end of the pile body, and a hydraulic jack fixed on a reaction frame is used for slowly pressing the underpinning pile into a hole which is pre-drilled in a foundation; wherein, the reaction frame is fixed on the surface of the foundation by the anchor rod, and the gravity of the upper structure provides the pile reaction force when the pile is pressed; after the pile is statically pressed to the designed depth, high-pressure grouting equipment is connected with the cavity of the pile body for pressure grouting, after grouting is completed, the upper end of the pile body is welded with the lower end of the pile head, anchor bars are inserted into anchor bar holes of the pile head and are lapped with original steel bars of the foundation, and then the pile and the foundation are formed into an effective whole by pouring early-strength concrete; after all underpinned piles are pressed, soil layer excavation and construction of structural columns, newly-built bottom plates and top plates are carried out; when the structural column, the newly added floor bottom plate and the top plate reach the design strength, the underpinning piles between the newly added basement top plate and the newly added basement bottom plate are cut off, and then the underpinning piles of the underground part are sequentially pulled out by using a pile pulling machine; and finally, grouting the pile hole by using high-pressure grouting equipment to fill and level up the pile hole.

The utility model discloses a theory of operation is: the grouting type profile steel underpinning pile for underground added layers has a cross-sectional area much smaller than that of a traditional prefabricated reinforced concrete pile and a traditional steel pipe pile, so that the soil squeezing effect is reduced; slurry overflow holes are distributed around the pile body and the pile tip, cement mortar can be injected into the gap between the pile and the soil to form a stone body, so that the pile body is more firmly connected with the surrounding soil body, and the bearing capacity of the pile is improved; the circular shell-shaped soil blocking cover is welded on the slurry overflow hole, so that the slurry overflow hole is not directly contacted with soil during pile driving, the blockage of the slurry overflow hole can be effectively prevented, the contact area between the pile body and the surrounding soil body is increased, and the engineering practicability is high; anchor bar holes are distributed on the pile head, anchor bars can be inserted into the anchor bar holes and then are lapped with original steel bars, and the pile is firmly combined with the structure foundation by pouring early-strength concrete; the underpinned pile is pulled out by a pile extractor after being cut off, and is recycled, so that the engineering cost is effectively saved; the pile head, the pile body and the pile tip are prefabricated and processed by a factory, so that the quality of welding seams can be effectively controlled, and the strength of each part is ensured.

The utility model has the advantages that: the grouting type profile steel underpinning pile for the underground added layer has smaller cross-sectional area than that of a traditional prefabricated reinforced concrete pile, and effectively reduces the soil squeezing effect; grouting holes are distributed on the pile body and the pile tip, and cement mortar can be injected into a gap between the pile and the soil body, so that the connection between the pile body and the surrounding soil body is more reliable, and the bearing capacity of the pile body is improved; anchor bar holes are distributed on the pile head, anchor bars are inserted into the anchor bar holes to be lapped with original steel bars, and then early strength concrete is poured to enable the pile to be combined with the structure foundation more firmly; the underpinned pile can be pulled out for recycling after being cut off, so that the engineering cost is saved; each part of the underpinning pile is prefabricated by a factory, the quality of a welding seam is ensured, and the strength of the component can meet the design requirement.

Drawings

Figure 1 is the utility model relates to a slip casting formula shaped steel underpins stake overall structure sketch map for underground increases layer.

Fig. 2 is the utility model relates to a slip casting formula shaped steel underpins stake pile head structural sketch for underground increases layer.

Fig. 3 is the utility model relates to a slip casting formula shaped steel underpins stake body structure sketch map for underground increases layer.

Fig. 4 is the utility model relates to a slip casting formula shaped steel underpins stake point structural sketch for underground increases layer.

Figure 5 is the utility model relates to a slip casting formula shaped steel underpins stake retaining cap structure enlargements for underground increases layer.

Illustration of the drawings: (1) -a shaft; (2) -a pile head; (3) -a pile tip; (4) -an anchor bar hole; (5) -a grout outlet.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in figure 1, a grouting type section steel underpinning pile for underground layer-adding consists of a pile body (1), a pile head (2), a pile tip (3), an anchor bar hole (4) and a grout overflow hole (5); pile body (1) cavity and all around distribute spill thick liquid hole (5), form by three H shaped steel welding, its cross-sectional shape: the middle part is a regular triangle, and three T-shaped flanges are distributed on the periphery of the middle part; the section of the pile head (2) is the same as that of the pile body (1), and anchor bar holes (4) are distributed on each flange web plate; the section of the upper end of the pile tip (3) is the same as that of the pile body (1), the lower end of the pile tip is a triangular cone welded by triangular steel plates, and the periphery of the pile tip is provided with slurry overflow holes (5); the anchor bar holes (4) are round holes, and the number and the size of the anchor bar holes are determined by the number and the thickness of steel bars needing to be anchored in the engineering; the slurry overflow hole (5) is a round hole with the diameter of 2 cm, and a round shell-shaped soil blocking cover is welded on the slurry overflow hole.

A grouting type profile steel underpinning pile for underground storey addition is characterized in that during construction, a pile body (1), a pile head (2) and a pile tip (3) which are prefabricated in a factory are transported to a construction position, the upper end of the pile tip (3) is welded with the lower end of the pile body (1), and the underpinning pile is slowly pressed into a hole which is pre-drilled in a foundation by a hydraulic jack fixed on a reaction frame; wherein, the reaction frame is fixed on the surface of the foundation by the anchor rod, and the gravity of the upper structure provides the pile reaction force when the pile is pressed; after the pile is statically pressed to the designed depth, high-pressure grouting equipment is connected with a pile body cavity for pressure grouting, after grouting is completed, the upper end of the pile body (1) is welded with the lower end of a pile head (2), anchor bars are inserted into anchor bar holes (4) of the pile head (2) and are lapped with original steel bars of a foundation, and then the pile and the foundation are formed into an effective whole by pouring early-strength concrete; after all underpinned piles are pressed, soil layer excavation and construction of structural columns, newly-built bottom plates and top plates are carried out; when the structural column, the newly added floor bottom plate and the top plate reach the design strength, the underpinning piles between the newly added basement top plate and the newly added basement bottom plate are cut off, and then the underpinning piles of the underground part are sequentially pulled out by using a pile pulling machine; and finally, grouting the pile hole by using high-pressure grouting equipment to fill and level up the pile hole.

Claims

1. a grouting type profiled steel underpinning pile for underground layering, is characterized in that, it is made up of pile body, pile head, pile tip, anchor reinforcement hole and overflow hole; Described pile body is hollow and surrounded by There are overflow holes, which are welded by three H-beams. The cross-sectional shape is a regular triangle in the middle, and three T-shaped flanges are distributed around; the cross-section of the pile head is the same as the pile body, and each flange web is Anchor reinforcement holes are distributed on the top; the upper end section of the pile tip is the same as the pile body, and the lower end is a triangular pyramid welded by triangular steel plates, surrounded by overflow holes; the anchor reinforcement holes are round holes, the number and size of which are determined by the project. It depends on the number and thickness of the steel bars to be anchored in; the slurry overflow hole is a circular hole with a diameter of 2 cm, and a circular shell-shaped soil retaining cover is welded on it.