CN103741724B - A kind of prefabricated prestressed underground continuous wall joint - Google Patents

Abstract

The invention discloses a joint of a prefabricated prestressed underground continuous wall, which comprises several joint sections sequentially connected from top to bottom. The joint section comprises two flange plates arranged in parallel and a web connecting the two flange plates. The center of the cross-section of the web is a ring, and the part of the ring that constitutes the ring protrudes toward the two sides connected with the underground continuous wall. Connecting plugs are arranged on the bottom surface of the segments, and the connecting plugs of one connecting segment are embedded in the inner circle of the connecting segment connected to it. The joint of the two joint segments is provided with a pre-embedded steel plate, and the pre-embedded steel plate is used for connecting The connecting steel plates of the two joint sections are connected, and prestressed tendon holes are longitudinally arranged in the flange plates. The invention provides a prefabricated prestressed underground diaphragm wall joint, which realizes an underground diaphragm wall joint with reasonable structure, reliable connection, excellent structural performance and high degree of industrialization.

Description

A prefabricated prestressed underground diaphragm wall joint

technical field

The invention relates to the field of design and construction of an underground diaphragm wall for building foundation pit engineering, in particular to a prefabricated prestressed underground diaphragm wall joint.

Background technique

The underground diaphragm wall construction technology originated in Europe. In 1938, Italy developed a construction method for constructing an underground diaphragm wall in a mud support deep groove. In 1950, it was the first to use deep mud tanks to build underground diaphragm walls in Italy. In the 1950s and 1960s, this technology was promoted in western developed countries, the former Soviet Union and Japan. In 1958, my country used this technology to build a dam cut-off wall. In the mid-1970s, this technology was applied to construction, coal mines and municipal industries. Due to its high rigidity, the underground diaphragm wall has the advantage of having little impact on the soil and structures around the foundation pit. It can be used as a retaining wall. With the improvement of the groove forming machine and the improvement of construction accuracy, it can also be used as the underground wall of the main structure. For exterior use.

The construction of the underground diaphragm wall is mainly divided into: guide wall construction, steel cage production, mud production, trough setting out, trough construction, hanging and placing steel cages, underwater concrete pouring, and trough section joint treatment, etc. The construction quality of the joint directly affects the overall construction quality of the underground diaphragm wall. If there is a problem at the joint, it will lead to problems such as leakage in the underground wall structure, which will affect the use of the underground structure. The underground diaphragm wall joints mainly include I-beam joints, locking pipes, etc. Among them, the upper and lower flanges of the I-shaped steel joints are welded together with the steel cage, and the overall mechanical performance of the underground diaphragm wall formed is good. However, the joint has quality defects such as concrete flow around and mud inclusion in the joint during the concrete pouring process. Concrete circumvention can cause the excavation of the subsequent underground continuous wall groove section to fail, and the I-beam web plate with mud can cause joint seepage. The main problems of lock pipe joints include: it is difficult to control the quality of the underwater operation, and it is easy to cause the lock pipe to tilt; the horizontal stiffness of the lock pipe is small, the lateral pressure is large during concrete pouring, and its verticality is difficult to control, resulting The vertical joints of the continuous wall are not straight and tight, and seepage is prone to occur; the pull-out time of the lock pipe is difficult to control, and quality accidents are prone to occur earlier than the initial setting time of the concrete, and the concrete has a large grip force later than the initial setting time , resulting in the phenomenon that the locking tube is difficult to pull out or even broken.

In summary, there is an urgent need for an underground diaphragm wall joint with reasonable structure, reliable connection, excellent structural performance, and high degree of industrialization.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a prefabricated prestressed underground diaphragm wall joint, which realizes an underground diaphragm wall joint with reasonable structure, reliable connection, excellent structural performance and high degree of industrialization.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A prefabricated prestressed underground diaphragm wall joint includes several joint sections connected sequentially from top to bottom. The joint section includes two parallel flange plates and a web connecting the two flange plates. The center of the section is a circular ring, and the part of the circular ring that constitutes the circular ring protrudes toward the two sides connected with the underground diaphragm wall. The bottom surface of the joint section arranged at the bottom is provided with a blade foot, and the bottom surface of the remaining joint sections A connecting plug is provided, the connecting plug of one connecting section is embedded in the inner circle of the connecting section connected to it, and a pre-embedded steel plate is arranged at the joint of the two joint sections, and the pre-embedded steel plate is connected with the two joint sections. The connecting steel plates are connected, and prestressed tendon holes are reserved longitudinally in the flange plates.

The connection plug is a hollow cylindrical structure, and the outer circumference of the connection plug is equal to the inner circumference of the ring.

The width of the flange plate is not less than 0.5m.

Beneficial effects of the present invention: 1. The center of the cross-section of the web according to the present invention is a circular ring, and the part of the circular ring that constitutes the circular ring protrudes toward the two sides connected with the underground diaphragm wall, which increases the bypass seepage path , effectively improves the shear strength of the joint with the underground diaphragm wall, and effectively solves the seepage problem of the underground diaphragm wall; 2, the present invention can realize the requirements of rapid construction, and the joint of the underground diaphragm wall is made in sections with appropriate lengths, which can be Realize factory prefabrication, adopt the structure of component fasting, solve the problem of transportation and hoisting; 3. The present invention is provided with connecting plug, and the connecting plug of one connecting section is embedded in the ring inner circle of the connecting section connected to it, and the connection of two joint sections There is a pre-embedded steel plate at the place, and the pre-embedded steel plate is connected with the connecting steel plate used to connect the two joint sections to ensure that the joint section can bear the load in the vertical and horizontal directions, which effectively improves the mechanical performance; 4. The present invention replaces the underground continuous The wall joint equipment replaces part of the cast-in-place underground continuous wall structure, eliminating the need to pull up the joint equipment, saving construction time and reducing cost; 5. The width of the two flange panels of the present invention is not less than 0.5m, ensuring the horizontal stiffness of the joint section and the length of the concrete bypass flow path, and the present invention does not need to reserve the clearance of the main reinforcement protective layer such as the I-shaped joint, which prevents the generation of bypass flow when the groove section is poured with concrete; 6. The bottom surface of the joint section arranged at the bottom of the present invention There are blade feet, which can be reliably cut into the soil by gravity and can be effectively fixed; 7. The flange plate of the present invention is longitudinally provided with reserved prestressed tendon holes, and the joints of the underground diaphragm walls are prestressed, which improves the resistance of the joints. Bending rigidity and crack resistance, so as to reduce the bending deformation of the joint, improve the durability of the joint, and at the same time ensure the verticality of the joint, ensure that the width of the construction width is within the design width, and also ensure the next construction width The width effectively improves the quality of the cast-in-place width of the underground diaphragm wall and ensures the overall rigidity of the connecting structure of the groove section of the underground diaphragm wall.

Description of drawings

Fig. 1 is a structural schematic diagram of a joint section of the present invention.

Fig. 2 is a structural schematic diagram of two connected joint sections according to the present invention.

Fig. 3 is a schematic diagram of the side structure of two connected joint sections according to the present invention.

Figure 4 is a cross-section of a joint section of the present invention.

Fig. 5 is a schematic plan view of the present invention and the cast-in-place groove section of the underground diaphragm wall.

Detailed ways

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

As shown in Figures 1, 2, 3, 4 and 5, a prefabricated prestressed underground diaphragm wall joint includes several joint sections 5 sequentially connected from top to bottom, and the joint section 5 includes two flanges arranged in parallel The plate 1 and the web connecting the two flange plates 1, the center of the cross-section of the web is a ring 3, the ring 3 protrudes toward the two sides connected with the underground continuous wall, and the ring 3 faces the flange plate The two sides of 1 are respectively connected to the web; the bottom surface of the joint section 5 arranged at the bottom is provided with a blade foot 8, and the bottom surface of the remaining joint sections is provided with a connecting plug 4, and the connecting plug 4 is a hollow cylindrical structure. The outer circumference of the plug 4 is equal to the inner circumference of the ring, and the connecting plug 4 of a connecting section 5 is embedded in the inner circle of the ring 3 of the connecting section connected to it, and the joint of the two joint sections 5 is provided with a pre-embedded steel plate 6 , the embedded steel plate 6 is connected with the connecting steel plate 7 used to connect the two joint sections 5, and the prestressed rib hole 2 is longitudinally arranged in the flange plate 1, and the width of the flange plate 1 is not less than 0.5m.

The underground diaphragm wall joint described above is divided into several joint sections 5, each joint section 5 is prefabricated in the factory according to the actual situation, and the center of the cross section of the web of each joint section 5 is a ring 3, forming a circle Part of the ring edge of ring 3 protrudes toward the two sides connected with the underground diaphragm wall. This structure not only solves the transportation and hoisting problems due to its light weight, but also increases the seepage path, effectively improving the connection with the underground diaphragm wall. The shear strength of the underground diaphragm wall effectively solves the seepage problem of the underground diaphragm wall; the width of the two flange plates 1 of each joint section 5 is designed to be not less than 0.5m to ensure the horizontal stiffness of the joint section and the length of the concrete flow path, and it is prefabricated The joint does not need to reserve the clearance of the main reinforcement protective layer like the I-shaped joint, which prevents the flow around when pouring concrete in the groove section; the bottom surface of the joint section 5 set at the bottom is provided with a blade foot 8, which can reliably cut into the soil by gravity, and can Effectively fixed; except for the joint section 5 at the bottom, the bottom surface of the other joint sections 5 is provided with a connecting plug 4, and the connecting plug 4 of one connecting section 5 is embedded in the inner circle of the ring 3 of the connecting section 5 connected to it. 5 is provided with a pre-embedded steel plate 6, and the pre-embedded steel plate 6 is connected with the connecting steel plate 7 used to connect the two joint sections 5 to ensure that the joint section 5 can bear vertical and horizontal loads, effectively improving the mechanical performance ; The flange plate 1 is longitudinally provided with reserved prestressed tendon holes 2, and the underground diaphragm wall joint is prestressed, which improves the bending stiffness and crack resistance of the joint, thereby reducing the bending deformation of the joint, Improve the durability of the joints and other effects, while ensuring the verticality of the joints, ensuring that the width of the construction width is within the design width, and also ensuring the width of the next construction width, effectively improving the quality of the cast-in-place underground diaphragm wall. The overall rigidity of the connection structure of the underground diaphragm wall groove section is guaranteed.

The underground diaphragm wall joint replaces the underground diaphragm wall joint equipment and replaces a part of the cast-in-place underground diaphragm wall structure. The specific construction process of the joint includes the following steps:

(1) Prefabricated underground diaphragm wall joints. The underground diaphragm wall joints are prefabricated on site or in a factory, and the underground diaphragm wall joints are divided into several joint sections 5 for prefabrication according to actual transportation capacity and hoisting restrictions.

(2) Locate the excavation position of the prefabricated underground diaphragm wall joint. The framing position of the underground diaphragm wall groove section is determined by measurement, the center of the joint is used as the groove forming and excavation positioning center, and the excavation depth is determined according to the measured height of the reinforced concrete guide wall top.

(3) Carry out groove-forming construction for the positioned underground diaphragm wall groove section. The positioned underground diaphragm wall groove section is excavated to the design depth and the bottom sediment is removed. The excavated groove section uses bentonite for mud wall protection; in order to ensure the stability of the groove wall, the mud quality is tested every 2 hours during the groove formation process, and Replace unqualified mud in time.

(4) Hoisting the prefabricated underground diaphragm wall joints. Specific hoisting steps: first, hang the joint section 5 at the bottom of the prefabricated underground diaphragm wall joint, set the anchorage end of the prestressed tendon, and then hoist another joint section 5, and the connecting plug 4 of the joint section 5 is embedded in the bottom joint section. In the inner circle of the ring of the joint section 5, the connecting steel plate 7 used to connect the two joint sections 5 is connected through the embedded steel plate 6, and the other joint sections 5 are spliced together in the same way to form a complete underground diaphragm wall joint. Align the center of the complete underground diaphragm wall joint with the center of the groove section, and monitor the verticality of the groove wall and the joint through ultrasonic waves. 0.5m, then apply prestress on the top joint section 5, and finally fix the top of the underground diaphragm wall joint on the guide wall.

(5) Clear holes for joints and pour concrete. Clean the hole first, and then pour concrete from the bottom of the underground diaphragm wall joint to the top of the joint after the clear hole is qualified.

(6) The statute of limitations is static. After the construction of the underground diaphragm wall joint is completed, it must be static for more than 48 hours to ensure that the soil around the underground diaphragm wall joint into the groove section is fully returned and compacted. After the report is solid, the adjacent cast-in-place underground continuous wall is carried out.

(7) Separate the underground diaphragm wall joint from the groove section. During the period when the soil body of the underground diaphragm wall joint forming a groove section is static, the adjacent underground diaphragm wall joints are continuously constructed. With this construction method, the underground diaphragm wall joint and the underground diaphragm wall groove section can be operated in flow, so that the underground diaphragm wall groove sections are all in accordance with Closed width construction ensures construction quality and construction period.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (3)

1. a prefabricated prestressed underground continuous wall joint, it is characterized in that: comprise the some joint junctions (5) connected successively from top to bottom, described junction (5) comprises two frange plates be arranged in parallel (1) and the web being connected two frange plates (1), the center of the cross section of described web is an annulus (3), annulus (3) is protruding towards the both sides be connected with diaphragm wall, and annulus (3) connects web respectively towards the both sides of frange plate (1); The bottom surface of the junction (5) bottom being arranged on is provided with sword pin (8), the bottom surface of all the other junctions is provided with attachment plug (4), the attachment plug (4) of a linkage section (5) embeds in annulus (3) inner circle of coupled linkage section, the junction of two junctions (5) is provided with pre-embedded steel slab (6), described pre-embedded steel slab (6) connects with the junction steel plate (7) in order to be connected two junctions (5), is vertically arranged with reserved presstressed reinforcing steel hole (2) in described frange plate (1).

2. a kind of prefabricated prestressed underground continuous wall joint according to claim 1, it is characterized in that: described attachment plug (4) is hollow cylinder structure, the outer perimeter of described attachment plug (4) and the inner circumferential appearance etc. of annulus (3).

3. a kind of prefabricated prestressed underground continuous wall joint according to claim 1, is characterized in that: the wide cut of described frange plate (1) is not less than 0.5m.