CN-117626969-B - Construction method of active water-blocking underground diaphragm wall

CN117626969BCN 117626969 BCN117626969 BCN 117626969BCN-117626969-B

Abstract

The invention provides a construction method of an actively water-blocking underground diaphragm wall, which comprises the following steps of S1, determining a construction sequence and construction indexes of the underground diaphragm wall outside a to-be-excavated area according to a design drawing, S2, excavating the underground diaphragm wall to a designed depth, S3, binding a reinforcement cage outside the underground diaphragm wall, enabling a guide pipe to pass through the middle of the reinforcement cage, S4, integrally placing the reinforcement cage and the guide pipe in S3 into the underground diaphragm wall, S5, pouring concrete into the underground diaphragm wall, S6, performing post-construction of dewatering well drilling after the concrete reaches strength, S7, enabling pore-forming equipment to pass through the guide pipe in the reinforcement cage, continuing to drill to a soil body boundary layer after the pore-forming equipment passes through the guide pipe completely, S8, performing post-construction of a water pump to pump, S9, excavating a foundation pit until the designed depth, S10, checking the state of the foundation pit, forming a sealing bottom, and pouring and filling the guide pipe. The invention has the advantages of ingenious design, wide application range and good economic benefit.

Inventors

HUANG WEI
LIU WEN
WANG ZHIMIN
ZHAO ZICHEN
ZUO YILIN
MA JINCHUAN
Fan jiao
WU YUCHEN

Assignees

中交二航局第一工程有限公司
中交第二航务工程局有限公司
中交武汉智行国际工程咨询有限公司

Dates

Publication Date: 20260508
Application Date: 20231219

Claims (5)

1. A construction method of an active water-blocking underground diaphragm wall is characterized by comprising the following steps: S1, determining the construction sequence and construction indexes of the underground continuous wall (1) outside the to-be-excavated area (2) according to a design drawing; s2, excavating the underground diaphragm wall (1) to a designed depth; S3, binding a reinforcement cage (3) outside the diaphragm wall (1), enabling the guide pipe (4) to penetrate through the middle of the reinforcement cage (3), and fixing the guide pipe (4) on the reinforcement cage (3) to form a whole; s4, integrally placing the reinforcement cage (3) and the guide pipe (4) in the S3 into the underground continuous wall (1); s5, pouring concrete (7) on the underground continuous wall (1); s6, after the concrete (7) reaches the strength, carrying out post-construction of dewatering well drilling construction; s7, the pore-forming equipment passes through the guide pipe (4) in the reinforcement cage (3) and continuously drills to the soil body boundary layer after completely penetrating through the guide pipe (4); S8, after the slag removal operation, installing a water suction pump in a later-used dewatering well, and performing water pumping construction; S9, excavating a foundation pit (8) until the design depth after the second water level (6) in the to-be-excavated area (2) and the first water level (5) outside the underground diaphragm wall (1) are lowered; S10, checking the state of the foundation pit (8), pouring concrete (7) at the bottom of the foundation pit (8) to form a back cover (9) after confirmation, and pouring and filling the guide pipe (4); in S3, an inner pipe (10) is connected to the inside of the guide pipe (4) through a C-shaped plate (16) and a lap plate (17), the inner pipe (10) is used for providing a stable working environment for a water suction pump, in S10, after confirmation, the inner pipe (10) is taken out of the guide pipe (4), a reinforcing steel bar frame (13) is placed in the inner pipe (10), and then the inside of the guide pipe (4) is filled by concrete (7) pouring; The method for installing the catheter (4) and the inner tube (10) in the S3 comprises the following steps: s31, the guide pipes (4) are in a split type connection structure, a plurality of guide pipes (4) are connected to form a whole, and a hollow groove (401) is formed in one side of each guide pipe (4) along the circumferential direction; s32, installing a C-shaped plate (16) at an inner side empty groove (401) of the guide pipe (4); s33, arranging a plurality of bridging plates (17) on the outer side of the inner tube (10) along the circumferential direction, wherein the bridging plates (17) are matched with the C-shaped plates (16) in shape, and the bridging plates (17) are detachably arranged on the C-shaped plates (16); s34, placing the inner tube (10) with the bonding plate (17) in the guide tube (4), and keeping the C-shaped plate (16) and the bonding plate (17) connected stably to form a section, wherein the C-shaped plate (16) and the bonding plate (17) are connected to form a supporting part; s35, splicing the sections in the S34, wherein supporting parts with different heights are arranged at intervals in a spiral mode, and a sufficient gap is reserved between projections at the bottom, so that overlapping and interference are avoided; s36, the C-shaped plate (16) and the lapping plate (17) are matched to form an accommodating space for pouring the concrete (7), the lapping plate (17) is taken away to form a supporting table (14) after the concrete (7) is fully solidified, and the reinforcing steel bar frame (13) is lapped on the supporting table (14); In S36, a first arc (1601) and a second arc (1602) are respectively arranged on two sides of the C-shaped plate (16), wherein the first arc (1601) is matched with the inner diameter of the catheter (4), and the second arc (1602) is matched with the lapping plate (17); In S36, the structure of the lapping plate (17) is that the lapping plate (17) comprises an L-shaped plate (1701), side plates (1702) are arranged on two sides of the L-shaped plate (1701), a shaping protrusion (1703) is arranged on the lower side of the middle part of the L-shaped plate (1701), the top of the C-shaped plate (16) is abutted against the lower part of the side plates (1702), the inner side width of the C-shaped plate (16) is smaller than the innermost distance between the two side plates (1702), the outer side width of the C-shaped plate (16) is smaller than the outermost distance between the two side plates (1702), and the shaping protrusion (1703) and the C-shaped plate (16) are matched to form a supporting table (14) and a groove (15); the steel bar frame (13) is structurally characterized in that the steel bar frame (13) comprises a straight bar (1301), a plurality of sleeves (1302) are uniformly sleeved on the straight bar (1301), a plurality of alignment bars (1303) are circumferentially distributed on the outer side of each sleeve (1302), and one side of each alignment bar (1303) is located in a groove (15).
2. The construction method of the active water-blocking underground diaphragm wall according to claim 1, wherein the lowest end of the guide pipe (4) is plugged by the bottom plate (12) before being lowered in the step S4.
3. The construction method of the active water-blocking underground diaphragm wall is characterized in that the two sides of the inner pipe (10) are respectively provided with a first step (1001) and a second step (1003), the first step (1001) is provided with an internal thread (1002), the second step (1003) is provided with an external thread (1004), the two adjacent inner pipes (10) are in threaded connection, the outer sides of the inner pipe (10) are further provided with mounting marks (1005), the mounting marks (1005) are used for distinguishing the mounting positions of the different inner pipes (10), the upper side and the lower side of the mounting marks (1005) are further provided with mounting alignment marks (1006), and when the two inner pipes (10) are mounted, whether the position of a lapping plate (17) is accurate or not is checked through the empty groove (401).
4. The construction method of the active water-blocking underground diaphragm wall according to claim 1, wherein in S31, two adjacent guide pipes (4) are spliced, and simultaneously the fixing component (11) is fixed at the joint of the two guide pipes (4).
5. The construction method of the active water-blocking underground diaphragm wall according to claim 4, wherein the structure of the guide pipe (4) is that a plurality of notches (402) are respectively arranged on two sides of the guide pipe (4) along the circumferential direction, annular grooves (403) are formed in one side of each notch (402), the fixing assembly (11) is composed of two semi-annular plates (1101) which are oppositely arranged, two raised strips (1102) are arranged on the inner sides of the semi-annular plates (1101) in parallel, the raised strips (1102) are located in the annular grooves (403), lug plates (1103) are arranged on two sides of the semi-annular plates (1101), and the two semi-annular plates (1101) are fixed through screws (1104) and nuts (1105).

Description

Construction method of active water-blocking underground diaphragm wall Technical Field The invention relates to the technical field of engineering construction, in particular to a construction method of an actively water-blocking underground diaphragm wall. Background With the rapid development of urban underground space development in China, underground continuous walls become a common structure for urban deep underground space development, and are mainly embodied as temporary supporting structures and permanent structures, and the advantages are proved in the process of urban underground space development. The underground diaphragm wall has the functions of water interception, seepage prevention, bearing, water blocking and the like, has the advantages of good integrity, high construction speed and the like, and is widely applied. The traditional underground diaphragm wall has good water interception and seepage prevention functions, but if the bottom of the traditional underground diaphragm wall is not embedded with a water barrier layer, the water interception and seepage prevention effects are poor, so that the traditional underground diaphragm wall is often large in pouring depth, and material waste is often caused. Although chinese patent CN 114150678A describes a foundation pit supporting structure of an underground diaphragm wall and a construction method thereof, the paper does not propose a more reasonable scheme for different depths of impervious layers of different soil properties, and the use has drawbacks, and chinese patent CN 219218960U describes an overall structure of a pile diaphragm wall, but the structure still has the problems described above, and thus needs improvement. Disclosure of Invention The invention provides a construction method of an actively water-blocking underground diaphragm wall, which solves the problems of inconvenient construction of the underground diaphragm wall, limited water blocking capacity, high construction cost and affected foundation pit construction on the inner side of the underground diaphragm wall. In order to solve the technical problems, the technical scheme adopted by the invention is that the construction method of the active water-blocking underground diaphragm wall comprises the following steps: s1, determining the construction sequence and construction indexes of the underground continuous wall outside the to-be-excavated area according to a design drawing; S2, excavating the underground diaphragm wall to a designed depth; S3, binding a reinforcement cage outside the diaphragm wall, enabling the guide pipe to pass through the middle of the reinforcement cage, and fixing the guide pipe on the reinforcement cage to form a whole; S4, integrally placing the reinforcement cage and the guide pipe in the S3 into a diaphragm wall; s5, pouring concrete to the diaphragm wall; S6, after the concrete reaches the strength, carrying out post-construction of dewatering well drilling construction; s7, enabling the pore-forming equipment to pass through a guide pipe in the reinforcement cage, and continuously drilling to a soil body boundary layer after completely penetrating through the guide pipe; S8, after the slag removal operation, installing a water suction pump in a later-used dewatering well, and performing water pumping construction; S9, excavating a foundation pit until the design depth after the second water level of the water level in the to-be-excavated area and the first water level of the water level outside the underground diaphragm wall are reduced; s10, checking the state of the foundation pit, pouring concrete at the bottom of the foundation pit after confirmation to form a back cover, and pouring and filling the guide pipe. In a preferred embodiment, the lowermost end of the conduit is plugged by a bottom plate prior to lowering in S4. In the preferred scheme, in S3, the inner pipe is connected with the interior of the guide pipe through the C-shaped plate and the lap plate and is used for providing a stable working environment for the water suction pump, in S10, after confirmation, the inner pipe is taken out of the guide pipe, a reinforcing steel bar frame is placed in the inner pipe, and then the interior of the guide pipe is filled with concrete pouring. In a preferred embodiment, the method for installing the catheter and the inner tube in S3 includes the steps of: s31, connecting a plurality of guide pipes into a whole by adopting a split type connecting structure, and processing empty slots on one side of the guide pipes along the circumferential direction; s32, installing a C-shaped plate at the inner side empty slot of the guide pipe; S33, arranging a plurality of lapping plates on the outer side of the inner tube along the circumferential direction, wherein the appearance of the lapping plates is matched with that of the C-shaped plate, and the lapping plates are detachably arranged on the C-shaped plate; s34, placing the inner tub