CN101225661A

CN101225661A - Pile-anchor foundation ditch supporting construction method

Info

Publication number: CN101225661A
Application number: CNA2008100596828A
Authority: CN
Inventors: 刘文革; 陈绍炳; 陶红雨; 童宏伟; 袁志明; 朱其良
Original assignee: ZHEJIANG HUANYU CONSTRUCTION GROUP
Current assignee: ZHEJIANG HUANYU CONSTRUCTION GROUP
Priority date: 2008-02-02
Filing date: 2008-02-02
Publication date: 2008-07-23
Anticipated expiration: 2028-02-02
Also published as: CN100465386C

Abstract

The invention discloses a foundation pit support method with pile and anchor, belonging to an external staying support technique field of the supporting structural retaining of the foundation pit, comprising that: a. bored piles are constructed to form a retaining wall, after lofting of the pile location according to the planar graph of the pile location; b. the soil is excavated to the bottom elevation of the top beam; c. the bored piles are chiseled to the design elevation; d. the first row of anchors are constructed in the soil layer between the adjacent bored piles; e. the top beams are constructed; f. the soil is excavated to the constructing position of the second row of anchors; g. the second row of anchors are constructed; h. the processes of f and g can be repeated until to the last row of anchors, according to different design conditions; i. the soil is excavated to the bottom of the foundation pit. The foundation pit support method with pile and anchor has the advantages of avoiding a lot of inner supports, providing an open working face for soil excavation, creating a good condition for mechanized construction, increasing the construction progress, needing not to treat the water stop of supporting, bracing substitution, dismantling support during the subsequent construction of the basement, convenient construction, increasing the progress, reducing the construction cost.

Description

Pile-anchor foundation ditch supporting construction method

Technical field

The invention discloses a kind of pile-anchor foundation ditch supporting construction method, belong to building foundation pit supporting engineering construction technical field.

Background technology

The existing building foundation pit supporting system has a variety of, and their each have their own advantages, the scope of application separately are also different.Wherein, it is more commonly used that stake adds supporting system, but it contains a large amount of interior supports, is not easy to cut the earth, structure construction, has influenced construction speed, has brought inconvenience also for simultaneously follow-up construction, influences construction speed.

Summary of the invention

In order to overcome above-mentioned shortcoming, but the invention provides a kind of reduction of erection time, accelerating construction progress, and can reduce the pile-anchor foundation ditch supporting construction method of cost.

To achieve these goals, the technical solution adopted in the present invention is: a kind of pile-anchor foundation ditch supporting construction method comprises: a. is according to the stake bit plan, carry out stake position setting-out after, carry out Bored Pile Construction again, form barricade; B. the absolute altitude at the bottom of the capping beam of cutting the earth; C. cut a hole bored pile to design elevation; D. carry out first row's anchor bolt construction in the soil layer between each adjacent bored pile; E. capping beam construction; F. cut the earth to second row's anchor bolt construction position; G. carry out second row's anchor bolt construction; H. according to different design conditions, can repeat the operation of f and g and arrange anchor pole to last; I. cut the earth to the foundation ditch bottom.

According to conditions such as foundation ditch engineering geology of living in, hydrogeology, clay distribution and physico-mechanical propertieses thereof, when requirement is made water-stop curtain with cement mixing pile, just should before described bored pile construction, carry out the construction of cement mixing pile earlier, form water-stop curtain.

Described first row's anchor pole, second row's anchor pole are prestressed anchor.

Pile-anchor foundation ditch supporting construction method of the present invention effectively combines bored pile construction and anchor bolt construction in deep excavation project, a large amount of interior supports have been removed from, provide open work plane to shoveling, create good condition to mechanized construction, accelerated construction speed, and in follow-up basement construction, need not handle and support sealing, support replacement, tear open the support processing, make things convenient for construction, accelerated progress, reduced cost.

Specifically, the present invention has following characteristics:

(1) stressed reasonable.Can make full use of the pulling force of the shear strength of the soil body with the balanced structure thing.Do not add the gravity and the drag that rely on self support structure and come the balance pulling force and do not resemble traditional stake.

Thereby can save construction investment in a large number, reduce construction costs.

(2) initiatively contend with.Prestressed anchor can provide enough drags once enforcement, limits the displacement of the soil body effectively.And a traditional mark structure stake propping is passive force structure, just can play one's part to the full after the soil body is subjected to displacement.

(3) improve the stress state of the soil body.Make the interior soil body of anchoring scope be in the compressive stress district, increased the stability of the soil body, and can improve the shear strength on weak structural plane or the slide surface.

(4) stake adds anchor, and the application point of anchor-holding force of anchor bolt and action direction can be chosen as required, thereby obtains best stablizing effect.

(5) in the work progress when the stratum condition changes, can in time adjust design parameters, the construction operating mode more gears to actual circumstances.

(6) can construct as usual under the narrow and small or geographical environment complicated situation at action space, need not to use big machinery.

(7) in deep foundation ditch soil excavation process, replace support with anchor pole, open shoveling work plane can be provided, created good condition to mechanized construction, accelerated speed of application.

(8) after stake added anchor and construct, basement structure construction can be constructed routinely, need not to do support place waterproofing work, and support replacement is torn support open and the post-processed of constructing such as handled, and has both made things convenient for construction, has guaranteed quality again, and has accelerated speed of application.

Description of drawings

The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments.

Fig. 1 is the plane structure schematic diagram of the specific embodiment of the invention;

Fig. 2 is that A among Fig. 1 is to elevation;

Fig. 3 is that B-B among Fig. 1 is to sectional view;

Fig. 4 is cement mixing pile construction schematic diagram;

Fig. 5 is the bored pile construction schematic diagram;

Fig. 6 is the schematic diagram of at the bottom of capping beam absolute altitude of cutting the earth;

Fig. 7 is the schematic diagram of cutter bored pile to design elevation;

Fig. 8 is the schematic diagram of first row's anchor bolt construction;

Fig. 9 is the schematic diagram of capping beam construction;

Figure 10 is for cutting the earth to the schematic diagram of second row's anchor bolt construction position;

Figure 11 is the schematic diagram of second row's anchor bolt construction;

Figure 12 is the schematic diagram to foundation ditch bottom of cutting the earth.

The specific embodiment

The invention will be further described below by specific embodiment, but the present invention is not limited by following examples.

The concrete construction sequence of pile-anchor foundation ditch supporting construction method embodiment 1 of the present invention is as follows:

1. according to the stake bit plan, carry out stake position setting-out after, carry out the construction of cement mixing pile 1 earlier, as shown in Figure 4, form water-stop curtain, carry out the construction of bored pile 2 again, as shown in Figure 5, form the barricade of bank protection retaining soil.

2. 3 absolute altitudes at the bottom of the capping beam of cutting the earth, as shown in Figure 6.

3. cutter bored pile 2 is to design elevation, as shown in Figure 7.

4. carry out first row's anchor pole 4a construction in the soil layer between each adjacent bored pile 2, and be prestressed anchor, as Fig. 1, Fig. 2, shown in Figure 8.

5. carry out capping beam 5 constructions, as shown in Figure 9.After capping beam 5 constructions, the end of first row's anchor pole 4a encloses purlin 6a by channel-section steel and locks mutually with capping beam 5, and the other end is anchored in the soil layer, as Fig. 2, shown in Figure 3.The first row anchor pole 4a, has further safeguarded the stable of the soil body and bored pile 2, thereby has reached the stable purpose of foundation ditch so can better bear the structure pulling force that is produced by soil pressure, water pressure etc. owing to adopt prestressed anchor.

6. cut the earth to second row's anchor pole 4b construction location, as shown in figure 10.

7. carry out second row's anchor pole 4b construction, and be prestressed anchor, as shown in figure 11.The end of second row's anchor pole 4b encloses purlin 6b by channel-section steel and locks mutually with bored pile 2, and the other end is anchored in the soil layer, as Fig. 2, shown in Figure 3.

8. cut the earth to the foundation ditch bottom, as shown in figure 12.

The concrete construction sequence of pile-anchor foundation ditch supporting construction method embodiment 2 of the present invention is identical with embodiment's 1, just because designed foundation depth is darker than embodiment 1, therefore need after second row's anchor pole 4b has constructed, append row's anchor bolt construction again, cut the earth at last to the foundation ditch bottom.

The construction principle of pile-anchor foundation ditch supporting construction method of the present invention is to utilize single bored pile 2 and

anchor pole

4a, 4b to form retaining soil series system.According to bored pile 2 stability checking computations and the safe and reliable requirements of foundation ditch strengthening; reach under the prerequisite of designing requirement in bored pile 2 quality own; adopt

anchor pole

4a, 4b to reinforce bored pile 2, form barricade and

anchor pole

4a, 4b combined supporting system, to guarantee the safety of excavation of foundation pit.The end of

anchor pole

4a, 4b locks mutually with capping beam 5, bored pile 2 respectively, the other end all is anchored in the upper strata, the load (power of toppling that the soil pressure of side direction, water pressure, buoyance in water and wind-force bring) that supporting and protection structure and other structures are born passes to anchoring body by the pull bar of

anchor pole

4a, 4b, and anchoring body will pass to the firm stratum of ground by frictional resistance resistance or supporting resistance from the power of pull bar again.

Pile-anchor foundation ditch supporting construction method of the present invention is applicable to deep-foundation pit engineering and space enclosing structures such as station, underground power house, underground garage, underground substation, basement in high rise building, is particularly useful for that the foundation ditch area is big, the deep foundation pit construction of absolute altitude complexity in the foundation ditch plane irregularity, same foundation ditch.

The quality specifications of cement mixing pile 1 of the present invention, bored pile 2 constructions is according to " building pile foundation tecnical regulations " (JGJ94-99) and national standard " Standard for quality inspection and assessment of buiding construction " pertinent regulations execution such as (GBJ301-88).The quality specifications of

anchor pole

4a, 4b construction be according to " Technical code for shotcrete rock bolts shore " (GBJ86-85) and " soil bolt design and construction standard " (CECS22:90) pertinent regulations carry out.Foundation ditch displacement deformation value is controlled at and is not more than 30mm.(existing national regulation is 30～50mm.)

Claims

1. pile-anchor foundation ditch supporting construction method is characterized in that:

A. according to the stake bit plan, carry out stake position setting-out after, carry out the construction of bored pile (2) again, form barricade;

B. (3) absolute altitude at the bottom of the capping beam of cutting the earth;

C. cut a hole bored pile (2) to design elevation;

D. carry out first row's anchor pole (4a) construction in the soil layer between each adjacent bored pile (2);

E. capping beam (5) construction;

F. cut the earth to second row's anchor pole (4b) construction location;

G. carry out second row's anchor pole (4b) construction;

H. according to different design conditions, can repeat the operation of f and g and arrange anchor pole to last;

I. cut the earth to the foundation ditch bottom.

2. according to the described pile-anchor foundation ditch supporting construction method of claim 1, it is characterized in that: before described bored pile (2) construction, carry out the construction of cement mixing pile (1) earlier, form water-stop curtain.

3. according to the described pile-anchor foundation ditch supporting construction method of claim 1, it is characterized in that: described first row's anchor pole (4a), second row's anchor pole (4b) are prestressed anchor.