CN108625356A - A kind of prefabricated prestressed underground continuous wall and its construction method - Google Patents

Abstract

The present invention relates to a kind of prefabricated prestressed underground continuous wall and its construction methods, diaphram wall includes a left side, right prefabricated prestressed underground continuous wall component, the transverse steel right end of left prefabricated prestressed underground continuous wall component is the first evagination connecting pin of evagination, the transverse steel left end of right prefabricated prestressed underground continuous wall component is the second evagination connecting pin of evagination, the straight lengths of rebar of first evagination connecting pin is on the outside of the bending reinforcing steel bar section of the second evagination connecting pin, left prefabricated prestressed underground continuous wall component, it is filled between the sides adjacent of right prefabricated prestressed underground continuous wall component and first evagination connecting pin, second evagination connecting pin and a left side, the sides adjacent of right prefabricated prestressed underground continuous wall component is consolidated into integrally-built cast-in-place concrete body.The present invention solves the problems, such as to be not easy to connect between two adjacent diaphram wall components in the prior art, while improving the intensity at street corner and impermeability.

Description

A prefabricated prestressed underground diaphragm wall and its construction method

technical field

The invention relates to a prefabricated prestressed underground continuous wall in the field of construction engineering and a construction method thereof.

Background technique

The underground diaphragm wall is mainly cast-in-place. The main construction steps of the traditional cast-in-place underground diaphragm wall are: firstly use professional trough-forming equipment to excavate the trough section, make the reinforcement cage after the trough is formed, then lift and lower the reinforcement cage, underwater Concrete is being poured and pile heads are being chiseled out. According to this step, the construction of one piece of ground connection wall is completed, and each piece of ground connection wall repeats the above steps. In the face of large-scale engineering construction, the traditional ground-to-wall structure has already encountered disadvantages such as high construction risk, high consumable materials, and high construction cost.

The prefabricated prestressed underground diaphragm wall is a good solution to the disadvantages of cast-in-place diaphragm walls. The existing prefabricated prestressed underground diaphragm wall is "a prefabricated pre-tensioned prestressed underground diaphragm wall" disclosed in Chinese patent CN205804324U. The wall is assembled on site by a number of prefabricated pretensioned prestressed underground diaphragm wall components. The components are divided along the height direction of the prefabricated, pre-tensioned and prestressed underground continuous components, the area with larger tension and two areas with smaller tension or compression located on both sides of the area with greater tension, and the pre-tensioned reinforcement is along the height of the underground continuous wall The whole length of the direction is arranged, that is to say, the pre-tensioned steel bars are arranged vertically, and the two ends of the pre-tensioned steel bars are respectively installed in the corresponding embedded casings. The small or compressed area has the same length along the height direction of the prefabricated pre-tensioned prestressed underground diaphragm wall member, and the pre-tensioned steel bars are only pre-stressed in the part located in the larger tension area.

In the existing underground diaphragm wall, pre-tensioned steel bars are arranged in the entire length of the ground connection wall components but not stretched over the entire length, and prestress is only applied in areas with large tension, which is conducive to the support of the ground connection wall as a maintenance structure. Under the complex environmental working conditions of the basement floor, the prestressing effect is more favorable. The ground connection wall components used in the prefabricated pre-tensioned prestressed ground connection wall are assembled on site, which not only saves materials, but also greatly saves labor costs. However, there are still the following problems: although the pre-tensioned steel bars are not stretched at full length, they need to be installed at the full length, resulting in a certain waste of pre-tensioned steel bars. In addition, the pre-tensioned steel bars generate vertical tension on the wall. In actual use, the direction of the load on the wall is mostly in the horizontal direction, and the pre-tensioned steel bars arranged in a vertical line cannot effectively resist the load in the horizontal direction. The overall tensile strength of the wall is not strong, and the wall The ductility before breaking the ring is not good; in addition, the adjacent sides of the two underground diaphragm wall components are flat, and the two underground diaphragm wall components are not easy to connect together, and the joints between the two underground diaphragm wall components are connected The strength is not enough, and the impermeability and sealing are not good.

Contents of the invention

The purpose of the present invention is to provide a prefabricated prestressed underground diaphragm wall to solve the problem that two adjacent underground diaphragm wall components are not easily connected in the prior art; Method of construction of continuous wall.

In order to solve the problems of the technologies described above, the technical scheme of the prefabricated prestressed underground diaphragm wall in the present invention:

A prefabricated prestressed underground diaphragm wall, comprising at least two prefabricated prestressed underground diaphragm wall members arranged in sequence from left to right, each prefabricated prestressed underground diaphragm wall member includes a wall body whose thickness extends along the front and back direction, and the wall body includes a steel cage and The prefabricated concrete body that is consolidated into an integral structure with the reinforcement cage, the reinforcement cage includes horizontal reinforcement and vertical reinforcement that are arranged crosswise, and defines the prefabricated prestressed underground diaphragm wall component that is located on the left among the two adjacent prefabricated prestressed underground diaphragm wall components It is a prefabricated prestressed underground diaphragm wall component on the left, and the prefabricated prestressed underground diaphragm wall component on the right is a right prefabricated prestressed underground diaphragm wall component. The first convex connection end of the prefabricated concrete body of the stress underground diaphragm wall component, the left end of the transverse reinforcement of the right prefabricated prestressed underground diaphragm wall component is the second convex of the prefabricated concrete body of the right prefabricated prestressed underground diaphragm wall component The connecting ends, the first protruding connecting end and the second protruding connecting end are staggered in the horizontal direction, and the adjacent sides of the left prefabricated prestressed underground diaphragm wall component and the right prefabricated prestressed underground diaphragm wall component are filled with the same The first convex connection end, the second convex connection end and the adjacent sides of the left and right prefabricated prestressed underground continuous wall components are consolidated into a cast-in-place concrete body of an integral structure.

The adjacent sides of the left prefabricated prestressed underground diaphragm wall component and the right prefabricated prestressed underground diaphragm wall component have connecting recesses opposite to the notches, and the connecting recesses extend along the up and down direction, and the cast-in-place concrete body fills the connecting recesses.

Both sides of the prefabricated concrete body in the thickness direction are provided with the transverse steel bars, the first protruding connecting end is a straight steel bar segment extending in the left and right directions, and the two second steel bars on both sides of the right prefabricated prestressed underground diaphragm wall member in the thickness direction The protruding connecting end is a bent steel bar segment facing oppositely bent, the bent steel bar segment is located inside the straight steel bar segment, and the end of the straight steel bar segment is connected with the bending starting point of the bent steel bar segment.

The two second convex connection ends on both sides of the right prefabricated prestressed underground diaphragm wall member in the thickness direction are arranged in a figure-eight shape.

The cast-in-place concrete body is also provided with a steel bar frame of the overall structure, and the second convex connection end is fixedly connected with the steel bar frame.

The prefabricated concrete body is provided with a hollow through hole penetrating the prefabricated concrete body along the up and down direction.

The wall is provided with at least two prestressed steel bars arranged at intervals along the left and right directions. The upper and lower ends of the prestressed steel bars are respectively fixed by the anchor structure of the upper prestressed steel bar and the lower end of the prestressed steel bar. An arc-shaped structure bent in the thickness direction of the body.

The same side of the wall is provided with an upper installation hole for the installation of the upper prestressed steel anchor structure and a lower installation hole for the installation of the lower prestressed steel anchor structure. The upper installation hole is gradually moving away from the arc from bottom to top. The oblique hole extends obliquely toward the arc top of the structure, and the lower mounting hole is an oblique hole extending obliquely away from the arc top of the arc structure from top to bottom.

The technical scheme of the construction method of prefabricated prestressed underground diaphragm wall in the present invention is:

A construction method for a prefabricated prestressed underground diaphragm wall, the method comprising the following steps: the first step is to put a clay curing agent in the excavated trench, and lower the left prefabricated prestressed underground diaphragm wall component into the excavated trench , during the lowering process, the mud containing the clay curing agent enters the hollow through hole of the left prefabricated prestressed underground diaphragm wall component; the second step is to connect the bottom of the right prefabricated prestressed underground diaphragm wall component to the left prefabricated prestressed underground diaphragm wall On the right side of the component, during the lowering process, the mud containing the clay curing agent enters the hollow through hole of the right prefabricated prestressed underground diaphragm wall component; the third step is to inject grout between the left and right prefabricated prestressed underground diaphragm wall components, Or insert a reinforcement frame between two adjacent prefabricated prestressed underground diaphragm wall components, fix the second protruding connection end of the right prefabricated prestressed underground diaphragm wall component with the connecting steel frame Grouting between diaphragm wall elements.

The beneficial effects of the present invention are: in the present invention, the left and right prefabricated prestressed underground diaphragm wall components are all prefabricated in the factory, and during on-site production, only the left and right prefabricated prestressed underground diaphragm wall components need to be poured and connected. When lowering the right prefabricated prestressed underground diaphragm wall component, since the first convex connection end is arranged staggered with the second convex connection end in the up-down direction, the first convex connection end will not interfere with the second convex connection end, and the two The two prefabricated prestressed underground diaphragm wall components can be placed relatively close to avoid the problem that the strength of the cast-in-place concrete body is too wide and the strength is affected. The second protruding connecting end of the component is used to form the steel skeleton of the cast-in-place concrete body, thereby ensuring the overall strength of the cast-in-place concrete body, thereby ensuring the connection strength between the two underground continuous wall components.

Description of drawings

Fig. 1 is the structural representation of an embodiment of prefabricated prestressed underground diaphragm wall among the present invention;

Fig. 2 is the structural representation of the prefabricated prestressed underground diaphragm wall member in Fig. 1;

Fig. 3 is A-A to sectional view among Fig. 2;

Fig. 4 is the B-B direction sectional view in Fig. 2;

Fig. 5 is a schematic diagram of the arrangement of prestressed steel bars at position C-C in Fig. 2;

FIG. 6 is an enlarged view of D in FIG. 5 .

Detailed ways

An embodiment of a prefabricated prestressed underground diaphragm wall is shown in Figures 1 to 6: it includes at least two prefabricated prestressed underground diaphragm wall components 23 arranged sequentially from left to right, and defines the location of two adjacent prefabricated prestressed underground diaphragm wall components. The left prefabricated prestressed underground diaphragm wall component is the left prefabricated prestressed underground diaphragm wall component, and the prefabricated prestressed underground diaphragm wall component on the right is the right prefabricated prestressed underground diaphragm wall component. The prefabricated prestressed underground diaphragm wall component includes a wall whose thickness extends in the horizontal direction. The wall includes a reinforcement cage and fiber concrete 1 consolidated with the reinforcement cage to form an integral structure. The reinforcement cage includes two rows located on both sides of the wall thickness. The vertical reinforcing bar 3 of the full length and the horizontal reinforcing bar 4 connected with the corresponding vertical reinforcing bar, the left end of the horizontal reinforcing bar 4 faces the relative bending to form a figure-eight structure 6, the right end of the transverse reinforcing bar is a straight reinforcing bar section 7, the figure-eight structure 6 and the straight The reinforcement sections 7 are all exposed structures, and the exposed structures and the corresponding concrete can form a joint 8 together. The straight reinforcement section 7 of the left prefabricated prestressed underground diaphragm wall component constitutes the first convex connection end, and the right prefabricated prestressed underground diaphragm wall component. The figure-eight structure constitutes the second convex connection end, and the heights of the first convex connection end and the second convex connection end are the same. The wall is provided with a plurality of hollow through holes 2 arranged at intervals along the left and right directions, and each hollow through hole 2 penetrates the wall along the up and down direction. The wall is provided with a plurality of corrugated pipes 5 arranged at intervals along the left and right directions, each corrugated pipe 5 is located between two corresponding hollow through holes, and prestressed steel bars 5 are pierced in each corrugated pipe, because the corrugated pipe is An arc-shaped structure bent along the thickness direction of the wall, so the corresponding prestressed steel bar is also an arc-shaped structure bent along the thickness direction of the wall. On the same side of the body of wall, an upper mounting hole 20 and a lower mounting hole 21 are provided, the upper mounting hole 20 is spaced from the upper end of the wall, the lower mounting hole 21 is spaced from the lower end of the wall, and the upper mounting hole is formed by The oblique hole gradually extends away from the arc top of the arc structure from bottom to top, and the lower installation hole is an oblique hole gradually extending away from the arc top of the arc structure from top to bottom, so that the installation hole and the bellows can be guaranteed The same direction, which is conducive to the penetration of prestressed steel bars, and also has the good tensile stress of prestressed steel bars. The aperture of the upper installation hole gradually becomes smaller from top to bottom, and the aperture of the lower installation hole gradually becomes smaller from bottom to top. The prestressed reinforcement anchorage structure includes an upper anchor plate 14 arranged in the upper mounting hole, and the lower end prestressed reinforcement anchorage structure includes a lower anchor plate arranged in the lower installation hole. The upper anchor plate 14 and the lower anchor plate are arranged obliquely. The two ends of the steel bars are respectively connected with anchor clips 16 for blocking and matching with the corresponding anchor plates, and the inner sides of the upper and lower anchor plates are provided with elastic spiral bars 12, and the upper ends of the prestressed steel bars form tension ends. The lower end of the steel bar forms the anchoring end, and the upper mounting hole and the lower mounting hole are tapered holes, and the prestressed steel bar is anchored by using the tapered hole to cooperate with the wedge and spiral bars of the corresponding anchor plate. The slope of the upper hole wall of the upper mounting hole is greater than the slope of the lower hole wall of the upper mounting hole; the slope of the upper hole wall of the lower mounting hole is greater than the slope of the lower hole wall of the lower mounting hole, which can be more convenient. Prestressed reinforcement for anchoring operations. A grouting hole 10 communicating with the bellows is provided on the wall, and an exhaust hole 11 is provided on the upper anchor plate. The adjacent sides of the left prefabricated prestressed underground diaphragm wall component and the right prefabricated prestressed underground diaphragm wall component are filled with the first convex connection end, the second convex connection end and the left and right prefabricated prestressed underground diaphragm wall components. A cast-in-place concrete body whose adjacent sides are consolidated into a monolithic structure.

The adjacent sides of two adjacent prefabricated prestressed underground diaphragm wall components are provided with connecting recesses 22 extending in the up and down direction opposite to the notches. Connection recess 22 . The prefabrication process of a single prefabricated prestressed underground diaphragm wall component in the factory is as follows: making a reinforcement cage through horizontal steel bars and vertical steel bars, presetting bellows, reserving hollow circular through holes, and performing fiber concrete pouring, fiber concrete pouring and bellows After pouring into the overall structure, the upper and lower mounting holes have also been formed. When the concrete strength reaches more than 80% of the design strength, the prestressed steel bars are inserted in the bellows, the prestressed steel bars are applied to the prestressed steel bars, and the prestressed forces are maintained by the cooperation of the spiral bars and the anchor plates with the tapered holes. The grout hole injects grout into the corrugated pipe, and the exhaust hole can ensure that the grout can fully wrap the prestressed steel bar, and pour the anchor concrete into the upper and lower mounting holes to avoid the anchorage from being exposed and rusted, and complete the single prefabricated underground wall component. make. In the present invention, the prestressed steel bars apply stress to the wall body after pouring, so the prefabricated prestressed underground diaphragm wall in the present invention is also called post-tensioned prefabricated prestressed underground diaphragm wall. The hollow through hole can not only improve the strength of the wall, but also speed up the construction speed. In addition, the hollow through hole can be equipped with circumferential steel bars and connectors, which is suitable for the "two walls in one" underground diaphragm wall. The horizontal steel bars on both sides of the wall and the The vertical reinforcement takes into account the superior structural properties of prestressed concrete and reinforced concrete, which can effectively control the cracks and deflection under the load, and has good ductility before failure. There are exposed steel bars on the adjacent sides of the two prefabricated prestressed underground diaphragm wall components, which fit each other when used, and the anti-seepage micro-expansion concrete joints are poured at the same time, which improves the strength and impermeability of the underground diaphragm wall joints and strengthens the structure of the underground diaphragm wall. Integrity, and the sealing effect of the joint is good. In other embodiments of the present invention: the upper end prestressed reinforcement anchorage structure and the lower end prestressed reinforcement anchorage structure can also be bolt-fixed structures or welded fixed structures; the number of prefabricated prestressed underground diaphragm wall components can also be three or four or other numbers; the heights of the first convex connection end and the second convex connection end can also be different.

The embodiment of the construction method of prefabricated prestressed underground diaphragm wall in the present invention: this method comprises the following steps: the first step: excavation trench, excavation trench can adopt multiple technology, available hydraulic grab machine digs groove, also can A double-wheel milling machine can be used for milling grooves, and a row drill type groove drilling machine can also be used to drill grooves; in the second step, the prefabricated prestressed underground diaphragm wall components are lowered into the grooves mixed with clay curing agent by lifting equipment, During the process of lowering the prefabricated prestressed underground diaphragm wall components, the mud containing the clay curing agent enters the hollow through hole of the wall, and the hollow through hole is filled with the mud containing the clay curing agent. Therefore, in the present invention, the hollow through hole can not only reduce the weight of the wall and reduce the amount of concrete used, but also reduce the resistance between the wall and the mud when it is lowered, and at the same time improve the resistance between the wall and the mud. The indirect contact area ensures the connection strength between the wall and the mud; the third step is to hang the next prefabricated prestressed underground diaphragm wall component so that the splayed end of the transverse steel bar of one prefabricated prestressed underground diaphragm wall component is located on the other prefabricated prestressed underground diaphragm wall component. Between the straight reinforcement sections of the transverse reinforcement of the prestressed underground diaphragm wall components, the eight-shaped ends are lapped and fixed with the corresponding transverse reinforcement bars. The fourth step is to pour concrete between two adjacent prefabricated prestressed underground diaphragm wall components, or to A connecting steel cage is inserted between two adjacent prefabricated prestressed underground diaphragm wall components, and the protruding transverse reinforcement of each prefabricated prestressed underground diaphragm wall component is fixed to the connecting steel cage, and then placed between two adjacent prefabricated prestressed underground diaphragm wall components. Concrete is poured in between, and the combination of wall components is formed after the concrete is cured, and a plurality of prefabricated prestressed underground diaphragm wall components form an integral underground diaphragm wall. In other embodiments of the present invention, the trench digging in the first step may not be a part of the construction method. There are already trenches on the construction site, and the prefabricated prestressed underground diaphragm wall components can be lowered directly during use.

Claims (9)

1. A prefabricated prestressed underground diaphragm wall, comprising at least two prefabricated prestressed underground diaphragm wall members arranged sequentially from left to right, each prefabricated prestressed underground diaphragm wall member includes a body of wall whose thickness extends along the front and rear directions, and the body of wall includes steel bars The cage and the prefabricated concrete body consolidated with the reinforcement cage into an integral structure are characterized in that the reinforcement cage includes horizontal reinforcement and vertical reinforcement arranged crosswise, and defines the prefabricated concrete body positioned on the left among two adjacent prefabricated prestressed underground diaphragm wall components. The prestressed underground diaphragm wall component is the left prefabricated prestressed underground diaphragm wall component, the prefabricated prestressed underground diaphragm wall component on the right is the right prefabricated prestressed underground diaphragm wall component, and the right end of the transverse reinforcement of the left prefabricated prestressed underground diaphragm wall component is The first convex connection end of the precast concrete body protrudes from the left prefabricated prestressed underground diaphragm wall component, and the left end of the transverse steel bar of the right prefabricated prestressed underground diaphragm wall component is the precast concrete protruding from the right prefabricated prestressed underground diaphragm wall component The second protruding connecting end of the body, the first protruding connecting end and the second protruding connecting end are staggered in the vertical direction, and the adjacent sides of the left prefabricated prestressed underground diaphragm wall component and the right prefabricated prestressed underground diaphragm wall component It is filled with a cast-in-place concrete body that is consolidated into an integral structure with the adjacent sides of the first convex connection end, the second convex connection end and the left and right prefabricated prestressed underground continuous wall components. 2. The prefabricated prestressed underground diaphragm wall according to claim 1, characterized in that: the adjacent side faces of the left prefabricated prestressed underground diaphragm wall member and the right prefabricated prestressed underground diaphragm wall member have notches opposite connecting recesses, The connection recess extends along the up and down direction, and the cast-in-place concrete body fills up the connection recess. 3. The prefabricated prestressed underground diaphragm wall according to claim 1, characterized in that: both sides in the thickness direction of the prefabricated concrete body are provided with the transverse reinforcing bars, and the first convex connecting end is a straight line extending along the left and right directions. Reinforcement bar section, the two second convex connection ends on both sides of the right prefabricated prestressed underground diaphragm wall member in the thickness direction are bent bar sections facing opposite bends, the bent bar section is located inside the straight bar section, and the straight bar section The ends are connected to the bend start of the bent bar segment. 4. The prefabricated prestressed underground diaphragm wall according to claim 3, characterized in that: the two second outwardly protruding connecting ends on both sides in the thickness direction of the right prefabricated prestressed underground diaphragm wall member are arranged in a figure-eight shape. 5. The prefabricated prestressed underground diaphragm wall according to claim 3, characterized in that: the cast-in-place concrete body is also provided with a steel bar frame of an integral structure, and the second convex connection end is fixedly connected with the steel bar frame. 6. The prefabricated prestressed underground diaphragm wall according to claim 1, characterized in that: the prefabricated concrete body is provided with a hollow through hole penetrating the prefabricated concrete body in the vertical direction. 7. The prefabricated prestressed underground diaphragm wall according to claim 1, characterized in that: the wall body is provided with at least two prestressed steel bars arranged at intervals along the left and right directions, and the upper and lower ends of the prestressed steel bars are prestressed by the upper end respectively. The reinforcement anchorage structure and the prestressed reinforcement anchorage structure at the lower end are fixed, and each prestressed reinforcement is an arc-shaped structure bent along the thickness direction of the wall. 8. The prefabricated prestressed underground continuous wall according to claim 7, characterized in that: the same side of the wall is provided with an upper mounting hole for the installation of the upper prestressed reinforcement anchorage structure and an upper installation hole for the lower prestressed reinforcement. The lower mounting hole for anchoring structure installation, the upper mounting hole is an inclined hole that gradually extends away from the arc top of the arc structure from bottom to top, and the lower mounting hole is gradually inclined from top to bottom away from the arc top of the arc structure Extended angled hole. 9. The construction method of prefabricated prestressed underground diaphragm wall is characterized in that: the method comprises the following steps: the first step is to put clay curing agent in the dug trench, and lower the left prefabricated prestressed underground diaphragm wall component to the In the dug trench, during the lowering process, the mud containing the clay curing agent enters the hollow through hole of the left prefabricated prestressed underground diaphragm wall component; in the second step, place the lower part of the right prefabricated prestressed underground diaphragm wall component to the left The right side of the prefabricated prestressed underground diaphragm wall component, during the lowering process, the mud containing the clay curing agent enters the hollow through hole of the right prefabricated prestressed underground diaphragm wall component; the third step, the left and right prefabricated prestressed underground diaphragm wall Grouting between the components, or inserting a reinforcement frame between two adjacent prefabricated prestressed underground diaphragm wall components, fixing the second protruding connecting end of the right prefabricated prestressed underground diaphragm wall component to the connecting reinforcement frame and then adjoining it Grouting between two prefabricated prestressed underground diaphragm wall elements.