CN102864946B - Process for supporting existing buildings through structural steel and horizontal rachel rod member and additionally adding multilayer basement - Google Patents

Abstract

The invention discloses a process of adding multi-layer basements to existing buildings supported by profiled steel plus horizontal tie rods, drilling pre-embedded profiled steels to support the existing buildings, and excavating the earthwork under the existing buildings. increase, the restraining effect of the soil on the section steel is weakened, and the stability of the section steel is reduced. Adding horizontal tie rods between the section steel can improve the stability of the excavated section steel. This method can realize the deep excavation of the earthwork under the existing building , and can add a multi-storey basement, using this method can realize the underground construction of the multi-storey basement of the strip-shaped foundation building, ensure the safety of the underpinning structure, and recycle the section steel and horizontal tie rods, reducing the cost.

Description

Technology of Adding Multi-storey Basement to Existing Building Supported by Sectional Steel and Horizontal Tie Rods

technical field

The invention relates to a building technology, in particular to a process for adding multi-storey basements to existing buildings supported by section steel plus horizontal tie rods.

Background technique

At present, the orderly, reasonable, comprehensive and efficient development and utilization of underground space resources of existing buildings has become one of the most effective ways to expand infrastructure capacity, improve urban comprehensive disaster prevention capabilities, improve land use efficiency and save land resources. According to the requirements of urban planning, most new buildings have considered the development and utilization of underground space. However, a large number of existing buildings have not designed underground parking lots due to historical reasons and lack of forward-looking. With the increase in the number of cars, it is difficult to park. Therefore, the development of the underground space of existing buildings is an arduous and urgent task.

Invention patents "Slab Foundation Underpinning Method" (ZL200610045257.4), "Static Pressure Pile Technology for Construction of Basement of Existing Buildings" (ZL200710116226.8), "Underground Layer Addition Technology of Frame Structure Building Independent Foundation Root-by-Root Underpinning Method" "(ZL201010226555.X), and the method of adding layers to the basement of existing buildings with independent foundations of frame structures (ZL201110075492.7) are all underground layer-adding methods for independent foundations of frame structures, but they are not suitable for strip foundations. In the paper "Experimental Research and Numerical Analysis of the Compressive Stability of High Cap Steel Pipe Pile", a method of using steel pipes on both sides of the wall to support the wall, cutting out the original foundation and adding a basement is proposed. However, this method is applicable to the underground layering of strip-shaped foundation buildings, but does not consider the tie between steel pipes to increase the stability of steel pipes, so it is not suitable for deep excavation to add multi-storey basements.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art, and to provide a process for adding multi-storey basements to existing buildings supported by section steel plus horizontal tie rods, which can realize the underground addition of multi-storey basements in strip-shaped basic buildings The project ensures the safety of the underpinning structure, and the recycling of section steel and horizontal tie rods reduces the cost.

To achieve the above object, the present invention adopts the following technical solutions:

A process of adding multi-storey basements to existing buildings with section steel plus horizontal tie rods. Drilling and pre-embedding section steel to support the existing buildings, and excavating the earth below the existing buildings. With the increase of the excavation depth of the earth, the soil will The restraining effect of the section steel is weakened, and the stability of the section steel is reduced. Adding horizontal tie rods between the section steel can improve the stability of the excavated section steel. This method can realize the deep excavation of the earthwork under the existing building, and can add For a multi-storey basement, the specific steps are as follows:

(1) Use drilling rig mud to protect the wall to form a hole, and the depth of the hole is to the bearing soil layer;

(2) After clearing the hole, pour concrete or cement mortar in the lower part of the hole until the position of the basement floor to be built;

(3) The construction underpinning beam clamps the existing building wall on both sides;

(4) Insert shaped steel within the height range of the proposed basement; the lower end of the shaped steel is anchored into the bearing soil layer under the floor of the proposed basement for at least 1m, and the upper end supports the underpinning cap connected to the underpinning beam;

(5) Pour sand, stone or concrete with the label C15 into the drilled hole where the section steel is inserted, so as to restrain the section steel and ensure the stability of the section steel;

(6) Excavate the earthwork under the existing building, and at the same time remove the sand, stone or concrete marked C15 around the section steel; after the earthwork under the foundation is excavated, the load of the existing building will be transferred to the section steel, and the original foundation can be cut off ;

(7) In order to ensure the stability of the section steel, a horizontal tie bar is set between the section steel for every excavation of 2 to 3 meters deep to ensure the stability of the section steel; the connection method between the section steel and the horizontal tie bar It can be welded or bolted; in order to protect the joint between the section steel and the horizontal tie rod from being polluted by mud or buried sand, stone, and concrete, before the section steel is inserted into the drill hole, cover the joint with plastic cloth or Packages such as linoleum;

(8) Excavate to the level of the floor of the multi-storey basement, construct the concrete cushion, the waterproof layer of the floor and the floor of the basement;

(9) Construct the basement wall at the middle position of each group of section steel, so that the plane position of the basement wall is consistent with that of the existing building wall;

(10) When the basement wall is poured to the bottom of the horizontal tie rods, the pre-embedded steel bars are connected to the section steel in the concrete basement wall, the original horizontal tie rods are removed, and the embedded steel bars replace the horizontal tie rods. To ensure the stability of the section steel; the horizontal tie rods were removed to form a large space to ensure the construction of concrete walls, beams and slabs;

(11) The basement wall is poured to the original existing building wall, and the two are connected with dry hard cement mortar or expansive concrete;

(12) Recycled section steel and horizontal tie rods.

The beneficial effect of the present invention is that, based on the principle of adding horizontal tie rods between the section steels (steel pipes or H-section steels) bearing vertical loads to improve the stability of the vertically compressed section steels, the invention proposes a horizontal tie section steel The process of supporting the underground growth of existing buildings: drilling pre-embedded steel to support the existing buildings, and excavating the earthwork under the buildings. As the excavation depth of the earth increases, the constraint effect of the soil on the section steel weakens, and the stability of the section steel decreases. The stability of the excavated steel can be improved by adding horizontal tie rods between the steel sections. The method can be used to realize deep excavation of the earthwork under the existing building, and can add multi-storey basement.

The method can be used to realize the underground layer adding project of the multi-storey basement of the strip-shaped foundation building, ensure the safety of the underpinning structure, recycle the section steel and the horizontal tie rods, and reduce the cost.

Description of drawings

Fig. 1 is the plane layout of the underpinning structure;

Fig. 2 is a schematic diagram of forming holes in the mud retaining wall;

Fig. 3 is a schematic diagram of inserted steel;

Fig. 4 is to excavate the earthwork and set the horizontal tie bar;

Fig. 5 is a horizontal arrangement diagram of horizontal tie rods;

Fig. 6 is a diagram of basement earthwork excavation completed and floor concrete poured;

Fig. 7 shows that the pre-embedded horizontal tie bar is connected with the section steel and the original horizontal tie bar is removed for pouring the basement wall;

Fig. 8 is to continue pouring basement body of wall and floor slab until connecting with existing building body of wall;

Fig. 9 is a drawing of removing and reclaiming steel pipes;

1—existing building wall; 2—underpinning beam; 3—underpinning cap; 4—section steel; 5—soil layer to be excavated for the proposed basement; 6—bearing soil layer ; 7—drilling; 8—horizontal tie rod; 9—basement floor; 10—basement wall; 11—basement floor.             

Detailed ways

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

As shown in Figure 1-9, the process of adding multi-storey basement to the existing building with section steel plus horizontal tie rods, drilling 7 pre-embedded section steel 4 to support the existing building, excavation is required to excavate the proposed basement under the existing building For the soil in the soil layer 5, as the excavation depth of the earth increases, the restraint of the soil on the steel 4 weakens, and the stability of the steel 4 decreases. Adding horizontal tie rods 8 between the steel 4 can improve the excavated steel. 4 stability, using this method can realize the deep excavation of the earthwork under the existing building, and can add multi-storey basement, the specific steps are as follows:

(1) Use drilling rig mud to protect the wall to form a hole, and the depth of the hole is to the bearing soil layer 6;

(2) After clearing the hole, pour concrete or cement mortar in the lower part of the hole until the position of the basement floor 9 to be built;

(3) The construction underpinning beam 2 clamps the existing building wall 1 on both sides;

(4) Insert section steel 4 within the height range of the proposed basement; the lower end of section steel 4 is anchored into the bearing soil layer 6 under the floor 9 of the proposed basement for at least 1m, and the upper end supports the underpinning cap 3 connected to the underpinning beam 2;

(5) Pour sand, stone or C15 concrete into the drill hole 7 where the steel 4 is inserted, to restrain the steel 4 and ensure the stability of the steel 4;

(6) Excavate the earthwork of the soil layer 5 that needs to be excavated for the proposed basement under the existing building, and remove the sand, stone or C15 concrete around the section steel 4 at the same time; after the earthwork under the foundation is excavated, the load of the existing building Transfer to section steel 4, the original foundation can be cut off;

(7) In order to ensure the stability of the section steel 4, a horizontal tie bar 8 is set between the section steel 4 for every 2 to 3 meters of earth excavated to ensure the stability of the section steel; the section steel 4 and the horizontal tie bar The connection method of the piece 8 can be welding or bolt connection; in order to protect the joint between the section steel 4 and the horizontal tie bar 8 from being polluted by mud or landfill sand, stone, and concrete, before the section steel 4 is inserted into the drilled hole , Wrap the joint with plastic cloth or linoleum;

(8) Excavate to the floor level of the multi-storey basement, construct concrete cushion, floor waterproof layer and basement floor 9;

(9) Construct the basement wall 10 at the middle position of each group of section steel 4, so that the basement wall 10 is consistent with the plane position of the existing building wall;

(10) When the basement wall 10 is poured to the bottom of the horizontal tie bars 8, the pre-embedded steel bars in the concrete basement wall 10 are connected to the section steel 4, the original horizontal tie bars are removed, and the embedded steel bars replace the horizontal tie bars. The tie rods ensure the stability of the section steel; the horizontal tie rods are removed to form a large space to ensure the construction of concrete basement walls, basement beams, and basement floors 11;

(11) The basement wall 10 is poured to the original existing building wall, and the two are connected with dry hard cement mortar or expanded concrete;

(12) Recycling section steel 4 and horizontal tie rods 8.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention. the

Claims (3)

1. add water flat tie bar of shaped steel supports existing building and sets up a multi-storey basement technique, it is characterized in that, the pre-buried shaped steel of holing is to support existing building, and horizontal tie bar is set up in the earthwork of excavation existing building below between shaped steel, and concrete steps are as follows:

(1) with rig mud off pore-forming, depth of pore forming is to bearing stratum;

(2) behind clear hole, in the bottom in hole concrete perfusion or cement mortar, until plan to build basement bottom board position;

(3) construction underpins beam and clamps existing building body of wall in both sides;

(4) planning to build basement altitude range insertion shaped steel; The support and connection of shaped steel upper end underpin the underpinning cap of pile of beam;

(5) in the boring of inserting shaped steel, pour into sand, stone or C15 concrete, shaped steel is produced to constraint, ensure the stability of shaped steel;

(6) excavate existing building below cubic metre of earth, remove the concrete of sand, stone or the C15 of shaped steel surrounding simultaneously; After the earthwork of below, basis is excavated, the load transfer of existing building is to shaped steel, by former basic amputation;

(7), for ensureing the stability of shaped steel, the earthwork that every excavation is 2 to 3 meters arranges horizontal tie bar together, to ensure the stability of shaped steel between shaped steel;

(8) be excavated to the floor level place of multi-storey basement, construction concrete cushion, base plate waterproofing and basement bottom board;

(9) at every group of shaped steel centre position construction basement wall, make basement wall consistent with on existing building wall plane position;

(10) basement wall is through concreting when the horizontal tie bar bottom, and in concrete basement body of wall, embedded bar is connected with shaped steel, removes former horizontal tie bar, and embedded bar replaces horizontal tie bar, guarantee shaped steel stability; Remove horizontal tie bar, formed large space, to ensure the construction of concrete wall, beam, plate;

(11) basement wall is built to former existing building body of wall place, both is connected by stiff cement mortar or expansive concrete;

(12) reclaim shaped steel and horizontal tie bar.

2. technique as claimed in claim 1, is characterized in that, described step (4) Shaped Steel lower end anchors in the bearing stratum of planning to build under basement bottom board at least 1m.

3. technique as claimed in claim 1, is characterized in that, described step (7) Shaped Steel is that welding or bolt are connected with the method for attachment of horizontal tie bar; Before shaped steel inserts boring, by Polypropylence Sheet or malthoid parcel for shaped steel joint.