CN107859036A - A kind of in-situ deposited prefabricated combining structure stake and its construction method suitable for karst region - Google Patents

Abstract

The invention discloses a kind of in-situ deposited prefabricated combining structure pile foundation and its construction method suitable for karst region,Including epimere stake and hypomere stake,Epimere stake is cast-in-place deposited reinforced concrete pile,Hypomere stake is prefabricated concrete tubular pile,Hypomere stake passes through the solution cavity area in rock stratum,Epimere stake passes through non-solution cavity area,And it is supported in hypomere stake upper end,Pile foundation is together to form with hypomere stake,During construction,First with the conventional method construction non-solution cavity area stake holes in upper strata,Then manually borehole method or rotary drilling rig construction lower floor solution cavity area stake holes,Concrete tubular pile is lifted into solution cavity area stake holes afterwards,And sealing ring is set between non-solution cavity area stake holes at the top of concrete tubular pile,Then the steel reinforcement cage of deposited reinforced concrete pile is lifted to non-solution cavity area stake holes,Cast-in-place construction obtains the overall pile foundation of concrete tubular pile and deposited reinforced concrete pile integration,Epimere stake and hypomere stake of the present invention are combined into an overall common stress of pile body,It is easy for construction,Fast,It is cheap.

Description

A cast-in-place prefabricated composite structural pile suitable for karst areas and its construction method

technical field

The invention belongs to the technical field of piles in civil engineering, and in particular relates to a cast-in-place prefabricated composite structure pile suitable for karst areas and a construction method thereof.

Background technique

When constructing pile foundations in karst-developed areas, when the borehole encounters a large-scale karst cave, the retaining wall mud in the borehole often loses rapidly and causes the hole to collapse, resulting in property loss and construction personnel casualties. Delay in construction period. In order to prevent such accidents, the usual practice is to drill steel pipe casings into the rock surface as a maintenance structure. This kind of steel casing is only a construction measure, and the force of the permanent structure does not take it into account, and it cannot be taken out after the pile is formed. , the cost is higher.

Contents of the invention

The purpose of the present invention is to provide a safe and economical cast-in-place prefabricated composite structural pile suitable for karst areas.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A cast-in-place prefabricated composite structural pile suitable for karst areas, comprising an upper section pile and a lower section pile, characterized in that: the upper section pile is a cast-in-place reinforced concrete pouring pile, the lower section pile is a prefabricated concrete pipe pile, and the lower section pile passes through the rock formation In the karst cave area, the upper section of piles passes through the non-karst cave area, and is supported on the upper end of the lower section of piles, and is combined with the lower section of piles to form a pile foundation.

As an improvement, the top of the prefabricated concrete pipe pile is provided with a reserved joint steel bar, and the upper section of the pile is cast-in-situ with the concrete pipe pile through the joint steel bar to form a cast-in-site prefabricated composite structural pile.

As an improvement, the lower end of the reinforcement cage of the reinforced concrete cast-in-situ pile extends into the hollow area of the concrete pipe pile to enhance the connection strength between the upper section pile and the lower section pile after cast-in-situ.

As an improvement, when the upper section of the pile is cast-in-situ, the hollow area of the lower section of the pile is also filled with core.

Another object of the present invention is a safe and economical construction method for cast-in-place prefabricated composite structural piles suitable for karst areas.

In order to achieve the above object, technical scheme of the present invention is as follows:

A construction method for cast-in-place prefabricated composite structural piles suitable for karst areas, characterized in that the method includes the following steps:

A Construct pile holes in the upper non-karst cave area by conventional construction methods;

B Use manual hole digging method or rotary drilling rig to construct pile holes in the lower karst cave area;

C. Set the top of the concrete pipe pile as the lower pile with an uninflated inflatable sealing ring, and hoist it into the pile hole in the lower karst cave area by means of a crane. The upper end of the inflatable sealing ring extends into the non-karst cave area for a certain length; inflatable sealing The ring is inflated to seal the gap between the pile hole and the top of the concrete pipe pile, so as to prevent the concrete from leaking into the cavity of the lower karst cave area during the casting process of the upper pile;

D Inflate the inflatable hole sealing ring to seal the gap between the top of the concrete pipe pile and the pile hole in the non-karst cave area, so as to prevent the concrete from leaking into the cavity of the lower karst cave area when the upper section of the pile is cast in-situ.

F hoist the reinforcement cage of the reinforced concrete cast-in-situ pile into the pile hole, pour concrete to form the concrete poured pile, and pour the concrete into the hollow area of the lower section of the pile to fill the core, and at the same time, use the joint reinforcement reserved at the top of the concrete pipe pile as the lower section of the pile to make the Concrete pipe piles and reinforced concrete cast-in-situ piles are combined into a whole pile body to bear the force together.

As an improvement, the inflatable sealing ring is replaced with an elastic rubber sealing ring.

Preferably, the core filling in the hollow area of the lower pile and the pouring of the upper pile are carried out at the same time.

Compared with the prior art, the present invention has the following advantages and effects: the reinforcement cage and concrete of the upper section of the pile extend into the appropriate length of the lower section of the pipe pile, so that the upper section of pile and the lower section of pile are combined into a whole pile body to bear the force together, and the construction is convenient and fast . The lower section of the pile is a concrete prefabricated pipe pile. During construction, there is no need to throw and fill the rubble in the cave to form a retaining wall or use a steel casing to protect the wall, which saves the cost of the steel casing in the cave area or the shortcoming of the long construction period of throwing and filling the rubble in the conventional method. It has the advantages of fast construction speed and low cost. The present invention replaces the conventional piles in the karst cave area with concrete pipe piles, and at the same time, the concrete pipe piles can be combined with the cast-in-place piles constructed later to form a permanent structure for joint stress, so it is an economical and practical pile foundation structure, and the economic benefits will be very high. obvious.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the cast-in-place prefabricated composite structural pile of the present invention.

Fig. 2 is an assembly diagram of the cast-in-place prefabricated composite structural pile assembly of the present invention.

Figures 3 to 7 are schematic diagrams of the construction process of cast-in-place prefabricated composite structural piles.

Among them, Figure 3 is the construction of pile holes in the upper non-karst cave area by conventional construction methods;

Fig. 4 is to utilize manual digging method or rotary drilling rig to construct pile holes in the lower layer karst cave area;

Fig. 5 is a schematic diagram of setting the top of the concrete pipe pile with an inflatable sealing ring and hoisting it into the pile hole in the lower karst cave area;

Fig. 6 is a schematic diagram of hoisting reinforced concrete cast-in-situ piles into the pile holes in the non-karst cave area, and inflating the inflatable sealing ring;

Fig. 7 is a schematic diagram of pouring concrete to form concrete pouring piles and filling concrete pipe piles.

1-upper section pile, 2-lower section pile, 3-inflatable sealing ring, 11-reinforced concrete pouring pile, 12-reinforcement cage, 21-joint steel bar, 22-concrete pipe pile, 1a-non-karst cave area 2a, 2a-karst cave area 2a, 3a - The cavities in the cave area.

Detailed ways

The present invention is further described below in conjunction with the accompanying drawings. The following is only an example of the technical solutions of the present invention, and does not represent the scope of all technical solutions of the present invention. In addition, the terms used in the embodiments have clear definitions, which are subject to their definitions, and there is no clear definition. The general explanations in the industry shall prevail, and the structure or steps not mentioned in the following embodiments are existing mature technologies.

As shown in Figures 1 and 2, a cast-in-place prefabricated composite structural pile suitable for karst areas includes an upper pile 1 and a lower pile 2, the upper pile 1 is a cast-in-place reinforced concrete pile 11, and the lower pile 2 is prefabricated Concrete pipe pile 22, the lower pile 2 passes through the karst cave area 2a in the rock formation, the upper pile 1 passes through the non-karst cave area 2a, and is supported on the upper end of the lower pile 2, and is combined with the lower pile 2 to form a pile foundation.

The top of the prefabricated concrete pipe pile 22 is provided with a reserved joint steel bar 21, and the reinforced concrete cast-in-situ pile 11 is integrated with the concrete pipe pile 22 through the joint steel bar 21 to form a cast-in-place prefabricated composite structural pile.

The lower end of the reinforcement cage 12 of the reinforced concrete cast-in-situ pile 11 extends into the hollow area of the concrete pipe pile 22 to enhance the connection strength between the upper section pile 1 and the lower section pile 2 after cast-in-situ, and when the upper section pile 1 is cast-in-situ, simultaneously give the lower section pile 2 The hollow area of the core is filled.

The present invention also provides an embodiment of a safe and economical construction method for cast-in-place prefabricated composite structural piles suitable for karst areas, specifically:

As shown in Figures 3 to 7, a construction method for cast-in-place prefabricated composite structural piles suitable for karst areas, the method includes the following steps:

A Construct the pile hole 2a in the upper non-karst cave area by conventional construction methods;

B Use manual hole digging method or rotary drilling rig to construct 2a pile holes in the lower karst cave area;

C. Set the top of the concrete pipe pile 22 as the lower pile 2 with an uninflated inflatable sealing ring, hoist it into the pile hole in the lower karst cave area 2a by means of a crane, and extend the upper end of the inflatable sealing ring into the non-karst cave area 2a for a certain length The inflatable sealing ring is inflated to seal the gap between the pile hole and the top of the concrete pipe pile 22, so as to prevent the concrete from leaking into the cavity 3a of the lower karst cave area during the cast-in-place process of the upper pile 1;

D inflates the inflatable hole-sealing ring to seal the gap between the top of the concrete pipe pile 22 and the pile hole in the non-karst cave area 2a to prevent the concrete from leaking into the cavity 3a of the lower karst cave area when the upper pile 1 is cast in-situ.

F hoist the reinforcement cage 12 of the reinforced concrete cast-in-place pile 11 into the pile hole, pour concrete to form the concrete cast-in-place pile, and pour the concrete into the hollow area of the lower pile 2 to fill the core. The joint reinforcement 21 makes the concrete pipe pile 22 and the reinforced concrete cast-in-situ pile 11 combined into a whole pile body to bear the force together.

The inflatable sealing ring 3 can be replaced by an elastic rubber sealing ring or other sealing devices.

Core filling in the hollow area of the lower pile 2 and pouring of the upper pile 1 are carried out simultaneously.

Claims (7)

1. a kind of in-situ deposited prefabricated combining structure stake suitable for karst region, including epimere stake and hypomere stake, it is characterised in that：Epimere Stake is cast-in-place deposited reinforced concrete pile, and hypomere stake is prefabricated concrete tubular pile, and hypomere stake passes through the solution cavity area in rock stratum, Epimere stake passes through non-solution cavity area, and is supported in hypomere stake upper end, and pile foundation is together to form with hypomere stake.

2. in-situ deposited prefabricated combining structure stake as claimed in claim 1, it is characterised in that：At the top of the prefabricated concrete tubular pile Provided with reserved joint reinforcing bar, epimere stake is cast as one structure by joint reinforcing bar and concrete tubular pile, is formed in-situ deposited prefabricated Combining structure stake.

3. combining structure stake as claimed in claim 1, it is characterised in that：The steel reinforcement cage lower end of the deposited reinforced concrete pile Hollow area in concrete tubular pile is extend into, strengthens cast-in-place rear epimere stake and hypomere stake bonding strength.

4. combining structure stake as claimed in claim 1, it is characterised in that：When epimere stake is cast-in-place, while to the sky of hypomere stake Core is filled out in heart district domain.

A kind of 5. in-situ deposited prefabricated combining structure pile construction method suitable for karst region, it is characterised in that step under this method bag：

A utilizes the conventional construction method construction non-solution cavity area stake holes in upper strata；

B utilizes manually digging hole method or rotary drilling rig construction lower floor solution cavity area stake holes；

C will be set with the inflation sealing of hole circle of unaerated as the concrete tubular pile top of hypomere stake, be lifted in the lump under by crane In floor solution cavity area stake holes, it is cased with inflation sealing of hole circle upper end and stretches into the non-segment length of solution cavity area one；

D gives the circle inflation of inflation sealing of hole, and space between concrete tubular pile top and non-solution cavity area stake holes is closed, prevents epimere stake from showing Concrete is leaked in lower floor's solution cavity area cavity when pouring；

The steel reinforcement cage of F lifting deposited reinforced concrete piles enters stake holes, and placing concrete forms cast-in-place concrete pile, and makes concrete Pour into hypomere stake hollow section to carry out filling out core, while by joint reinforcing bar reserved at the top of the concrete tubular pile as hypomere stake, make Concrete tubular pile and deposited reinforced concrete pile are combined into an overall common stress of pile body.

6. in-situ deposited prefabricated combining structure pile construction method as claimed in claim 5, it is characterised in that：The gas-flow closure circle replaces It is changed to flexible rubber seal.

7. in-situ deposited prefabricated combining structure pile construction method as claimed in claim 5, it is characterised in that：Hypomere stake hollow section is carried out Fill out core and epimere stake is poured while carried out.