CN1405409A

CN1405409A - Foundation pit side-wall flexible support method

Info

Publication number: CN1405409A
Application number: CN 02130834
Authority: CN
Inventors: 贾金青; 宋二祥
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-10-11
Filing date: 2002-10-11
Publication date: 2003-03-26
Anticipated expiration: 2022-10-11
Also published as: CN1167857C

Abstract

The invention refers to a flexible-supporting and protecting method of inner wall of the base pit. At first dig, then make the hole toward the earth-facing surface, and place the anchor shaft in the hole, and then pour the plasm into the hole, and set the earth-stopping surface layer on the surface of basic pit wall, set the load bearing body on the anchor shaft on the earth-stopping surface layer, and the end of the anchor shaft reaches out of the load bearing body, and then exert the prestressing force on the anchor shaft and use the anchor to lock it, and then repeat the above course until to the fundus.

Description

A kind of flexible support method of foundation pit side-wall

Technical field

The present invention relates to a kind of flexible support method of foundation pit side-wall, belong to the supporting of ground foundation engineering technical field, particularly foundation pit side-wall.

Background technology

Foundation pit supporting method commonly used in the existing ground foundation engineering is, piling bar, the steel concrete of doing foundation pit enclosure structure earlier give system stake, deposited reinforced concrete pile or diaphragm wall, and then carry out the excavation of foundation ditch, when digging when anchor pole is layouted projected depth, carry out anchor bolt construction to foundation pit side-wall.This job practices, long construction period not only, construction costs height, and when running into perpendicular hard formation, piling bar, steel concrete give system stake or castinplace pile and are difficult to reach and give the depthkeeping degree, as take explosion, not only expense increases, and easy shock collapse hole wall, and base is to the safety that jeopardizes the foundation ditch adjacent structure.

Summary of the invention

The objective of the invention is to overcome the shortcoming of prior art, propose a kind of flexible support method of foundation pit side-wall,, and improve working security with reduction of erection time, reduction cost, the distortion of control hole wall effectively.

The flexible support method of the foundation pit side-wall that the present invention proposes may further comprise the steps:

1, the excavation 1-3 rice that faces down from ground;

2, towards meeting native face perforate, the aperture is 50-170mm;

3, in the hole, put into anchor bar body, in the hole, be in the milk then;

4, the native surface layer of retaining is set on the surface of foundation pit walls;

5, in the anchor pole end supporting body is set, the supporting body on the native surface layer of retaining is stretched out in the end of anchor pole;

6, anchor pole is applied prestressing force, and lock with anchor head;

7, repeat said process, until substrate.

Retaining soil surface layer in the said method can adopt linked network shotcrete layer or wood layer.

Supporting body in the said method is channel-section steel, i iron or other shaped steel, and its arrangement mode can be vertically placement or laterally placement, can the continuous or single span freely-supported of multispan when laterally placing.

Anchor bar body can be any in reinforcing bar, steel pipe or the steel strand in the said method.

Anchor pole is divided into free section and anchoring section in the said method, and the free section part of anchor pole twines Polypropylence Sheet or sleeving plastic pipe, and anchor bar body and cement mortar are isolated.

Anchor pole in the said method can become the cross arrangement of plum blossom shape.

The flexible support method of the foundation pit side-wall that the present invention proposes, need not do piling bar, steel concrete and give system stake, deposited reinforced concrete pile or diaphragm wall, can the supporting while excavating at the construction field (site), therefore, short construction period, construction costs are low, the distortion of hole wall is little, and can guarantee the retaining wall quality, improve working security.

Description of drawings

Fig. 1 is the schematic diagram of the invention process first floor dado structure.

Fig. 2 is the schematic diagram that utilizes the whole dado structure that method of the present invention finishes.

Fig. 3 is as the channel-section steel of supporting body or i iron, the schematic diagram of vertically arranging on the native face of retaining.

Fig. 4 is as the channel-section steel of supporting body or i iron, the horizontal two continuously arranged schematic diagrames that collapse on the native face of retaining.

Among Fig. 1～Fig. 4, the 1st, the hole, the 2nd, anchor bar body, the 3rd, cement mortar or cement paste, the 4th, Polypropylence Sheet or plastic bushing, the 5th, free section, the 6th, anchoring section, the 7th, keep off native surface layer, the 8th, supporting body, the 9th, anchor head.

The specific embodiment

The flexible support method of the foundation pit side-wall that the present invention proposes, the excavation 1-3 rice that at first faces down from ground, towards meeting native face perforate 1, the aperture is 50-170mm; Put into anchor bar body 2 in hole 1, wherein anchor bar body twines plastics or plastic pipe 3 at free segment limit, is in the milk 4 then in the hole; Form free section 5 of anchor pole and anchoring section 6, the native surface layer 7 of retaining is set on the surface of foundation pit walls; Anchor pole end on the native surface layer of retaining is provided with supporting body 8, and supporting body is stretched out in the end of anchor pole; Anchor pole is applied prestressing force, and lock with anchor head 9; Repeat said process, until substrate.

Retaining soil surface layer in the said method can be layer of concrete or wood layer.Supporting body can be channel-section steel or i iron, and its arrangement mode can be vertically placement or laterally placement, can the continuous or single span freely-supported of multispan when laterally placing.

Anchor pole is divided into free section and anchoring section in the said method, and the free section part of anchor pole twines Polypropylence Sheet or sleeving plastic pipe 4, and anchor bar body and cement mortar are isolated.

Anchor pole in the said method can become the cross arrangement of plum blossom shape, as shown in Figure 3 and Figure 4.

The concrete construction sequence of this method is: be suitable for the foundation trench that panelling construction makes things convenient for the width and the degree of depth along excavating foundation trench sideline inner edge excavation, in the vertically certain depth place boring 1 under the ground level of foundation trench sidewall, in the hole, put into anchor bar body 2, wherein anchor rod body twines Polypropylence Sheet or sleeving plastic pipe 3 at free segment limit, cementing mortar or cement paste 4 in the hole, form free section 5 of anchor pole and anchoring section 6, assembling reinforcement net on foundation pit side-wall, sprayed mortar then, steel mesh reinforcement and concrete form sidewall steel concrete and keep off native surface layer 7 or lay plank on foundation pit side-wall, form plank and keep off native surface layer 7, by anchor head 9 pressure-bearing body 8 and steel concrete are kept off native surface layer or plank again and keep off native surface layer and connect, constitute one deck retaining wall.Repeat above-mentioned working procedure, finish following each layer retaining wall,, constitute whole support system until substrate.

One embodiment of the present of invention are, during construction, at first in this zone, excavate wide 6m along excavation of foundation pit sideline inner edge, the foundation trench of dark 3m, in the vertically 2m place boring 1 under the ground level of foundation trench sidewall, 15 ° of bore angles, manufacturing two diameters is Φ 25 anchor pole muscle 2, and twines three road Polypropylence Sheets 3 at free segment limit, puts it in the hole, perfusion M25 plain-water slurry 4 in the hole, form anchor pole, rock-bolt length is divided into free section 5 and anchoring section 6, and the level interval of anchor pole on the out-of-the-way wall of foundation ditch also is 2m, after the first floor anchor bolt construction is intact, assembling reinforcement net on foundation pit walls, its specification are that diameter is 6mm, spacing is 200mm, and sprayed mortar is to half of design thickness then, the sprayed mortar label is C20, thickness 100.Vertically by putting supporting body, supporting body is made of 2 No. 12 channel-section steels at the anchor pole end, and its length is 1500, and then sprayed mortar is to design thickness.Steel mesh reinforcement and concrete form sidewall steel concrete surface layer 7.Anchor head 9 by anchor pole connects supporting body and steel concrete surface layer again, constitutes the first floor retaining wall, treats that bolt cement slurry intensity reaches 15Mpa, when the surfacing steel bar concrete strength reaches 10MPa, anchor pole applied prestressing force, has promptly finished the first floor retaining wall.Repeat above-mentioned working procedure, finish following each layer retaining wall, the levels anchor pole is arranged and is quincunx, until substrate, constitutes whole support system.

Claims

1, a kind of flexible support method of foundation pit side-wall is characterized in that this method comprises following each step:

(1) the excavation 1-3 rice that faces down from ground;

(2) towards meeting native face perforate, the aperture is 50-170mm;

(3) in the hole, put into anchor bar body, in the hole, be in the milk then;

(4) the native surface layer of retaining is set on the surface of foundation pit walls;

(5) in the anchor pole end supporting body is set, the supporting body on the native surface layer of retaining is stretched out in the end of anchor pole;

(6) anchor pole is applied prestressing force, and lock with anchor head;

(7) repeat said process, until substrate.

2, the method for claim 1 is characterized in that retaining soil surface layer wherein is layer of concrete or wood layer.

3, the method for claim 1 is characterized in that supporting body wherein is channel-section steel or i iron.

4, the method for claim 1, the arrangement mode that it is characterized in that channel-section steel wherein or i iron are lateral cross or vertically intersect.

5, the method for claim 1 is characterized in that anchor bar body is any in reinforcing bar, steel pipe or the steel strand.

6, the method for claim 1 is characterized in that anchor pole wherein is divided into anchoring section in the free section, and the free section part of anchor pole twines Polypropylence Sheet or sleeving plastic pipe, and anchor bar body and cement mortar are isolated.

7, the method for claim 1 is characterized in that anchor pole wherein becomes the cross arrangement of plum blossom shape.