Waterproof supporting structure in water-rich soft soil area and construction method

Abstract

The application provides a water-blocking supporting structure in a water-rich soft soil area and a construction method. The water-blocking supporting structure is formed by a plurality of supporting steel sheet piles which are sequentially and oppositely engaged. The supporting steel sheet pile comprises an inner sleeve steel sheet pile and an outer sleeve steel sheet pile sleeved outside the inner sleeve steel sheet pile. A plurality of supporting plates are arranged in the gap between the inner sleeve steel sheet pile and the outer sleeve steel sheet pile. The opening end of the outer sleeve steel sheet pile is provided with a sealing plate for sealing the opening end. The opening end of the outer sleeve steel sheet pile is provided with engaging grooves at both edges. By adopting the double-layer structure of the outer sleeve steel sheet pile and the inner sleeve steel sheet pile and connecting the two layers by the supporting plates and the sealing plate, the supporting strength of the steel sheet pile can be effectively enhanced, and the water-blocking supporting structure can better adapt to the adverse geological conditions in the water-rich soft soil area.

Description

Technical Field

[0001] The present invention relates to the field of water-blocking support structures, and in particular to a water-blocking support structure in a water-rich soft soil area and a construction method thereof. Background Art

[0002] my country's southeastern coastal areas contain extensive soft marine sedimentary silt soils characterized by high moisture content, poor permeability, long consolidation times, high compressibility, and low bearing capacity. When subjected to external compressive loads, soft soils exhibit significant drainage, consolidation, and rheological characteristics. Construction of foundation pits or underground spaces on such soils can lead to collapse, posing challenges to safety and stability during construction and operation. Therefore, addressing the large deformation and water resistance of soft soil slopes under external loads has become a pressing issue for foundation pits and underground spaces.

[0003] At present, during the retaining construction, the commonly used technical means are steel sheet pile cofferdam or reinforced concrete sheet pile cofferdam. However, in the unfavorable geological conditions of water-rich soft soil areas, insufficient support bearing capacity is prone to occur, resulting in sand, mud and water gushing, and even foundation pit collapse. Therefore, a water-blocking support structure and construction method in water-rich soft soil areas are proposed to solve the above problems. Summary of the Invention

[0004] The main purpose of the present invention is to provide a water-blocking support structure and construction method in water-rich soft soil areas to solve the problem of insufficient support bearing capacity caused by adverse geological conditions in water-rich soft soil areas, resulting in sand, mud and water gushing, and even foundation pit collapse.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a water-blocking support structure in a water-rich soft soil area is composed of a number of supporting steel sheet piles that are interlocked one by one. The supporting steel sheet piles include an inner steel sheet pile and an outer steel sheet pile that is mounted on the outside of the inner steel sheet pile. A number of support plates are arranged in the gap between the inner steel sheet pile and the outer steel sheet pile. The open ends of the outer steel sheet pile and the inner steel sheet pile are provided with sealing plates to close them, and interlocking grooves are provided at both edges of the open end of the outer steel sheet pile.

[0006] In a preferred embodiment, a plurality of slots are formed between the support plate and the outer steel sheet piles and the inner steel sheet piles, and between the inner steel sheet piles and the closing plate, and reinforcement structures are inserted into the slots.

[0007] In the preferred embodiment, the reinforcement structure includes a top plate and a geobag arranged at the bottom of the top plate with a number matching the slots. The top plate is provided with a pouring hole connected to the pouring port of the geobag. Reinforcement mortar is poured in the geobag. The size of the top plate is the same as the size of the top of the supporting steel sheet pile.

[0008] In the preferred embodiment, the geobag is composed of a casting section, a plurality of connecting sections and a base connected in sequence;

[0009] A pouring port is provided on the top of the pouring section, and the pouring port of the pouring section is fixed on the bottom surface of the top plate through the pouring hole;

[0010] The connecting section includes a connecting stainless steel ring and a tensile geobag arranged at the bottom of the stainless steel ring;

[0011] The base comprises a bottom stainless steel ring and a high-strength tensile bag arranged at the bottom of the bottom stainless steel ring.

[0012] In a preferred embodiment, the tensile geotextile bag is formed by bonding a base layer, a plurality of tensile strips equidistantly distributed on the outside of the base layer, and an outer layer in sequence from the inside to the outside. The polyester outer layer is provided with a plurality of staggered perforations, the number of which is the same as the number of tensile strips, and the tensile strips pass through and into the perforations.

[0013] The pouring section is made of a base layer and a polyester outer layer bonded together from the inside to the outside;

[0014] The base layer consists of two polyester fiber spunlace non-woven fabric layers and a HDPE plastic anti-seepage layer, and the HDPE plastic anti-seepage layer is bonded between the two polyester fiber spunlace non-woven fabric layers;

[0015] Both the tensile strips and high-strength tensile bags are made of glass fiber base cloth and PTFE coating.

[0016] In a preferred embodiment, the outer portion of the connecting stainless steel ring of the topmost connecting section and the bottom of the top plate are both provided with corresponding hanging ears, and a hanging chain is provided between the corresponding hanging ears.

[0017] In the preferred embodiment, a plurality of irregularly distributed first protrusions are provided on the wall surface of the support plate and the inner steel sheet pile and the inner wall surface of the outer steel sheet pile, and a plurality of irregularly distributed second protrusions are provided on the outside of the tensile geobag.

[0018] The method includes:

[0019] S1. Use trenching equipment to dig trenches at the support locations, and perform dewatering and trench cleaning procedures in the trenches;

[0020] S2. Place the supporting steel sheet piles into the groove one by one, and make each supporting steel sheet pile engage with each other through the engaging groove;

[0021] S3. Then, place each geobag of the reinforcement structure into the corresponding slot on the supporting steel sheet pile, and place the top plate cover on the top of the supporting steel sheet pile;

[0022] S4. Grouting is performed on each pouring hole on the top plate in sequence, so that each geobag is filled with reinforcement mortar;

[0023] S5. Then grout the remaining space in the groove and complete the water-blocking support construction after it solidifies.

[0024] In the preferred embodiment, the specific grooving method in step S1 is: using a hydraulic grab and a hydraulic double-wheel milling machine for construction, specifically including:

[0025] S1. Use a hydraulic grab to dig into the sand layer at two locations along the guide wall at appropriate intervals, i.e., dig two side holes;

[0026] S2. Use hydraulic double-wheel milling to mill the side holes to the final hole depth;

[0027] S3. Repeat step S1 for the unexcavated area within the central soil range of the two side holes, leaving enough original soil between the central grab excavation hole and the side holes to ensure the stability of the trough and to retain the soil size to facilitate grab milling.

[0028] S4. Repeat step S3 for the remaining unexcavated area within the two side holes.

[0029] S5, using a hydraulic double-wheel milling machine to mill the middle hole dug in step S3 and step S4 to the final hole depth;

[0030] S6. Use a hydraulic grab to dig the original soil remaining in the trench section to the sand layer;

[0031] S7. After the original soil remaining in the trench section is excavated to the sand layer, a hydraulic double-wheel milling machine is used to mill the remaining original soil to the final hole depth, that is, the trench excavation is completed by multiple trenches.

[0032] In the preferred solution, during the construction process of the hydraulic grab and hydraulic double-wheel milling, mud wall protection construction is carried out on the excavated hole, wherein the mud mix ratio is: water: bentonite: CMC: sodium carbonate: barium sulfate = 1000:2:20:30.

[0033] The present invention provides a water-blocking support structure and construction method for water-rich soft soil areas, which has the following beneficial effects:

[0034] 1. By adopting a double-layer structure of outer steel sheet piles and inner steel sheet piles, and connecting the two with support plates and sealing plates, the supporting strength of the steel sheet piles can be effectively enhanced, and they can better adapt to the adverse geological conditions of water-rich soft soil areas;

[0035] 2. By setting up a reinforcement structure in the slot formed by its structure, the support strength can be further enhanced. At the same time, the use of geobags to pour reinforcement mortar can improve the construction efficiency of the reinforcement structure without affecting the recycling of the supporting steel sheet piles, and make the reinforcement structure fit better with the slot;

[0036] 3. By using geobags composed of a pouring section, multiple connecting sections and a base, and through the partition of multiple stainless steel rings and the design of tensile strips, the tensile strength of the geobags can be effectively enhanced, making the geobags suitable for the long vertical use of supporting steel sheet piles;

[0037] 4. By adopting the combined construction of hydraulic grab bucket and hydraulic double-wheel milling machine, the trenching efficiency of a single trench section is greatly improved, the trenching time of super-long trenches is greatly shortened, and the risk of trench wall collapse is reduced. By using mud with a ratio of water: bentonite: CMC: sodium carbonate: barium sulfate = 1000:2:20:30 for mud wall protection construction, the mud density can be effectively increased, the mud viscosity and sand content can be controlled, the mud stability can be increased, and the water loss rate can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below with reference to the accompanying drawings and examples:

[0039] Figure 1 This is a diagram of the bite connection structure of the supporting steel sheet piles of the present invention;

[0040] Figure 2 This is a structural diagram of the supporting steel sheet pile of the present invention;

[0041] Figure 3 This is a top view of the supporting steel sheet pile structure of the present invention;

[0042] Figure 4 This is a cross-sectional structural diagram of the supporting steel sheet pile of the present invention;

[0043] Figure 5 This is a structural diagram of the connection between the supporting steel sheet pile and the reinforcement structure of the present invention;

[0044] Figure 6 This is an exploded view of the connection structure between the supporting steel sheet pile and the reinforcement structure of the present invention;

[0045] Figure 7 This is a structural diagram of the connection between the geobag and the top plate of the present invention;

[0046] Figure 8 This is a cross-sectional view of the geobag structure of the present invention;

[0047] Figure 9 This is a structural diagram of the tensile geobag of the present invention;

[0048] Figure 10 This is a cross-sectional view of the connection structure between the geobag and the support plate of the present invention;

[0049] In the figure: supporting steel sheet pile 1; outer steel sheet pile 101; inner steel sheet pile 102; support plate 103; sealing plate 104; bite groove 105; slot 106; reinforcement structure 2; top plate 21; geobag 22; casting section 220; connecting section 221; connecting stainless steel ring 2210; tensile geobag 2211; polyester fiber spunlace non-woven fabric layer 2212; HDPE plastic anti-seepage layer 2213; tensile strip 2215; polyester cloth outer layer 2216; second protrusion 2217; first protrusion 2218; casting hole 23; base 223; bottom stainless steel ring 2230; high-strength tensile bag 2231. DETAILED DESCRIPTION

[0050] Example 1

[0051] like Figure 1-10 As shown, it is composed of several supporting steel sheet piles 1 that are interlocked with each other one by one. The supporting steel sheet piles 1 include an inner steel sheet pile 102 and an outer steel sheet pile 101 that is sleeved on the outside of the inner steel sheet pile 102. The inner steel sheet pile 102 and the outer steel sheet pile 101 can be one of a U-shaped steel sheet pile and a V-shaped steel sheet pile. In this embodiment, the U-shaped steel sheet pile is the most preferred. Several support plates 103 are welded in the gap between the inner steel sheet pile 102 and the outer steel sheet pile 101. The support plates 103 are arranged vertically and extend from the top of the inner steel sheet pile 102 and the outer steel sheet pile 101 to their bottom. In this embodiment, In this example, the number of support plates 103 is eight, and a support structure is formed between the inner steel sheet pile 102 and the outer steel sheet pile 101 by the eight support plates 103. The outer steel sheet pile 101 and the open end of the inner steel sheet pile 102 are welded with a sealing plate 104 to seal them. The sealing plate 104 seals the opening of the outer steel sheet pile 101 and the inner steel sheet pile 102. Both edges of the open end of the outer steel sheet pile 101 are provided with an integrally formed bite groove 105, thereby forming a higher strength water-blocking support structure through the inner steel sheet pile 102, the outer steel sheet pile 101 and the support plate 103.

[0052] In the preferred embodiment, a plurality of slots 106 are formed between the support plate 103 and the outer steel sheet pile 101 and the inner steel sheet pile 102, as well as between the inner steel sheet pile 102 and the closing plate 104. In this embodiment, nine slots 106 are formed, and a reinforcement structure 2 is inserted into the slot 106. The strength of the supporting steel sheet pile 1 can be further enhanced by the reinforcement structure 2.

[0053] In the preferred embodiment, the reinforcement structure 2 includes a top plate 21 and geobags 22 arranged at the bottom of the top plate 21 and the number of which is adapted to the slots 106. The top plate 21 is provided with pouring holes 23 connected to the pouring ports of the geobags 22. Reinforcement mortar is poured in the geobags 22. The size of the top plate 21 is the same as the size of the top of the supporting steel sheet pile 1. Due to the characteristics of the geobag 22 itself, it is convenient to quickly place it into the slot 106, and it can perfectly adapt to the shape of the slot 106 after pouring the reinforcement mortar.

[0054] When in use, the geobags 22 are placed in the corresponding slots 106 in sequence, and the top plate 21 is covered on the top of the supporting steel sheet pile 1. Then, the reinforcing mortar is poured into the geobags 22 in sequence through the pouring holes 23 in sequence, so as to utilize the solidified reinforcing mortar to improve the strength of the supporting steel sheet pile 1.

[0055] In the preferred embodiment, the geobag 22 is composed of a casting section 220, a plurality of connecting sections 221 and a base 223 connected in sequence. The number of connecting sections 221 is determined according to the actual length of the supporting steel sheet pile 1.

[0056] A pouring port is provided at the top of the pouring section 220 , and the pouring port of the pouring section 220 passes through the pouring hole 23 and is bonded to the bottom surface of the top plate 21 ;

[0057] The connecting section 221 includes a connecting stainless steel ring 2210 and a tensile geobag 2211 bonded to the bottom of the stainless steel ring 2210, wherein the top of the connecting stainless steel ring 2210 is bonded to the bottom end of the casting section 220 or the bottom end of the tensile geobag 2211 of the previous section;

[0058] The base 223 includes a bottom stainless steel ring 2230 and a high-strength tensile bag 2231 arranged at the bottom of the welded stainless steel ring 2230 . The bottom stainless steel ring 2230 is bonded to the bottom end of the upper tensile geobag 2211 .

[0059] By providing multiple connecting stainless steel rings 2210 and bottom stainless steel rings 2230 , the overall strength of the geobag 22 is improved.

[0060] It should be noted that during pouring, the base 223 is in contact with the bottom of the trench, reducing the stress on the entire geobag 22 .

[0061] In a preferred embodiment, the tensile geotextile bag 2211 is formed by bonding a base layer, a plurality of tensile strips 2215 equidistantly distributed on the outside of the base layer, and an outer layer 2216 in sequence from the inside out. The polyester outer layer 2216 is provided with a plurality of staggered perforations, the number of which is the same as the number of tensile strips 2215. The tensile strips 2215 pass through and in through the perforations, thereby utilizing the tensile strips 2215 to improve the overall tensile resistance.

[0062] The casting section 220 is formed by bonding the base layer and the polyester outer layer 2216 in sequence from the inside to the outside;

[0063] The base layer is composed of two polyester fiber spunlace non-woven fabric layers 2212 and a HDPE plastic anti-seepage layer 2213. The HDPE plastic anti-seepage layer 2213 is bonded between the two polyester fiber spunlace non-woven fabric layers 2212.

[0064] The tensile strip 2215 and the high-strength tensile bag 2231 are both composed of a glass fiber base cloth and a PTFE coating.

[0065] In the preferred embodiment, a corresponding number of hanging ears 224 are fixed to the outside of the connecting stainless steel ring 2210 of the top connecting section 221 and the bottom of the top plate 21, and a hanging chain 225 is provided between the relative hanging ears 224, thereby improving the connection strength of the geobag 22 by providing the hanging chain 225.

[0066] In the preferred embodiment, a number of irregularly distributed first protrusions 2218 are provided on the wall surface of the support plate 103 and the inner steel sheet pile 102, as well as the inner wall surface of the outer steel sheet pile 101, and a number of irregularly distributed second protrusions 2217 are provided on the outside of the tensile geobag 2211. When the tensile geobag 2211 is poured with reinforcing mortar, it expands to form the same shape as the slot 106, and makes part of the second protrusions 2217 overlap with part of the first protrusions 2218. At the same time, the first protrusions 2218 will conflict with the tensile geobag 2211, forming multiple points of contact.

[0067] Example 2

[0068] Further illustrate with reference to Example 1, Figure 1-10 The structure shown is a water-blocking support construction method in a water-rich soft soil area, which includes:

[0069] S1. Use trenching equipment to dig trenches at the support locations, and perform dewatering and trench cleaning procedures in the trenches;

[0070] S2. Place the supporting steel sheet piles 1 into the groove one by one, and make each supporting steel sheet pile 1 engage with each other through the engaging groove 105;

[0071] S3, then put each geobag 22 of the reinforcement structure 2 into the corresponding slot 106 on the supporting steel sheet pile 1, and cover the top plate 21 on the top of the supporting steel sheet pile 1;

[0072] S4, grouting each casting hole 23 on the top plate 21 in sequence, so that each geobag 22 is filled with reinforcement mortar;

[0073] S5. Then grout the remaining space in the groove and complete the water-blocking support construction after it solidifies.

[0074] In the preferred embodiment, the specific grooving method in step S1 is: using a hydraulic grab and a hydraulic double-wheel milling machine for construction, specifically including:

[0075] S1. Use a hydraulic grab to dig into the sand layer at two locations along the guide wall at appropriate intervals, i.e., dig two side holes;

[0076] S2. Use hydraulic double-wheel milling to mill the side holes to the final hole depth;

[0077] S3. Repeat step S1 for the unexcavated area within the central soil range of the two side holes, leaving enough original soil between the central grab excavation hole and the side holes to ensure the stability of the trough and to retain the soil size to facilitate grab milling.

[0078] S4. Repeat step S3 for the remaining unexcavated area within the two side holes.

[0079] S5, using a hydraulic double-wheel milling machine to mill the middle hole dug in step S3 and step S4 to the final hole depth;

[0080] S6. Use a hydraulic grab to dig the original soil remaining in the trench section to the sand layer;

[0081] S7. After the original soil remaining in the trench section is excavated to the sand layer, a hydraulic double-wheel milling machine is used to mill the remaining original soil to the final hole depth, that is, the trench excavation is completed by multiple trenches.

[0082] The combined use of a hydraulic grab bucket and a hydraulic twin-wheel milling machine can effectively address the potential for backfill boulders in the overburden layer, which can affect twin-wheel milling efficiency. Muddy soil layers can easily cause the milling head of a twin-wheel milling machine to become stuck, significantly reducing the efficiency of twin-wheel milling. The grab bucket has low efficiency in sand, gravel, and rock formations, and repeated lifting creates excessive disturbance, easily leading to instability of the trench wall and rapid deterioration of mud properties.

[0083] This construction method not only leverages the advantages of hydraulic troughing machines in soft clay formations, such as fast troughing, high precision, and minimal mud contamination, but also avoids the drawbacks of double-wheel milling machines, which are prone to wheel sticking and the generation of large amounts of waste slurry in these formations. Furthermore, by leveraging the double-wheel milling machine's troughing speed advantages in deep formations, pebbles, and rock formations, the combined application of the two processes significantly improves the troughing efficiency of individual trough sections, significantly shortens the troughing time for extremely long troughs, and reduces the risk of trough wall collapse.

[0084] In the preferred solution, during the construction process of the hydraulic grab and hydraulic double-wheel milling, mud wall protection construction is carried out on the excavated hole, wherein the mud mix ratio is: water: bentonite: CMC: sodium carbonate: barium sulfate = 1000:2:20:30.

[0085] In order to ensure that the other performance indicators of the mud are maintained, through research and experiments on external additives, barite (BaSO4), CMC and sodium carbonate are used as additives to effectively increase the mud density, control the mud viscosity and sand content, increase the mud stability and reduce the water loss rate.

[0086] Through further proportioning experiments, the optimal mud mix ratio is water: bentonite: CMC: sodium carbonate: barium sulfate = 1000:2:20:30. If the content of admixture (BaSO4) is further increased, the colloid rate of the mud will decrease and the thickness of the mud skin will increase.

[0087] Indoor mud standing test table According to the results of indoor experiments, the mud with this ratio can remain stable for 8 days.

[0088] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A water-blocking support structure in a water-rich soft soil area, which is formed by a plurality of supporting steel sheet piles (1) interlocked with each other, and is characterized by: The supporting steel sheet pile (1) comprises an inner steel sheet pile (102) and an outer steel sheet pile (101) sleeved outside the inner steel sheet pile (102); a plurality of support plates (103) are provided in the gap between the inner steel sheet pile (102) and the outer steel sheet pile (101); a sealing plate (104) is provided at the open ends of the outer steel sheet pile (101) and the inner steel sheet pile (102); and a bite groove (105) is provided at both edges of the open end of the outer steel sheet pile (101); A plurality of slots (106) are formed between the support plate (103) and the outer steel sheet piles (101) and the inner steel sheet piles (102), and between the inner steel sheet piles (102) and the closing plate (104), and the reinforcing structures (2) are inserted into the slots (106); The reinforcement structure (2) includes a top plate (21) and geobags (22) arranged at the bottom of the top plate (21) and having a number matching that of the slots (106). The top plate (21) is provided with pouring holes (23) connected to the pouring openings of the geobags (22). Reinforcement mortar is poured into the geobags (22). The size of the top plate (21) is the same as that of the top of the supporting steel sheet pile (1). The geobag (22) is composed of a casting section (220), a plurality of connecting sections (221) and a base (223) connected in sequence; A pouring port is provided at the top of the pouring section (220), and the pouring port of the pouring section (220) passes through the pouring hole (23) and is fixed on the bottom surface of the top plate (21); The connecting section (221) includes a connecting stainless steel ring (2210) and a tensile geobag (2211) arranged at the bottom of the stainless steel ring (2210); The base (223) includes a bottom stainless steel ring (2230) and a high-strength tensile bag (2231) arranged at the bottom of the bottom stainless steel ring (2230); The base (223) is in contact with the bottom of the trough during pouring.

2. The water-blocking support structure for water-rich soft soil areas according to claim 1 is characterized by: The tensile geotextile bag (2211) is formed by bonding a base layer, a plurality of tensile strips (2215) equidistantly distributed outside the base layer, and an outer layer (2216) in sequence from the inside out. The polyester outer layer (2216) is provided with a plurality of staggered perforations, the number of which is the same as the number of the tensile strips (2215), and the tensile strips (2215) pass through and into the perforations. The casting section (220) is formed by bonding the base layer and the polyester cloth outer layer (2216) in sequence from the inside to the outside; The base layer is composed of two polyester fiber spunlace non-woven fabric layers (2212) and a HDPE plastic anti-seepage layer (2213), and the HDPE plastic anti-seepage layer (2213) is bonded between the two polyester fiber spunlace non-woven fabric layers (2212); The tensile strip (2215) and the high-strength tensile bag (2231) are both composed of glass fiber base cloth and PTFE coating.

3. The water-blocking support structure in water-rich soft soil area according to claim 1 or 2, characterized in that: The outside of the connecting stainless steel ring (2210) of the topmost connecting section (221) and the bottom of the top plate (21) are both provided with corresponding hanging ears (224), and a hanging chain (225) is provided between the corresponding hanging ears (224).

4. The water-blocking support structure for water-rich soft soil areas according to claim 1 is characterized by: A plurality of irregularly distributed first protrusions (2218) are provided on the wall surface of the support plate (103) and the inner steel sheet pile (102), as well as on the inner wall surface of the outer steel sheet pile (101), and a plurality of irregularly distributed second protrusions (2217) are provided on the outside of the tensile geobag (2211).

5. The construction method of the water-blocking support structure in water-rich soft soil area according to any one of claims 1 to 4, characterized in that: The method includes: S1. Use trenching equipment to dig trenches at the support locations, and perform dewatering and trench cleaning procedures in the trenches; S2, placing the supporting steel sheet piles (1) into the grooves one by one, and making each supporting steel sheet pile (1) engage with each other through the engaging grooves (105); S3, then placing each geobag (22) of the reinforcement structure (2) into the corresponding slot (106) on the supporting steel sheet pile (1), and placing the top plate (21) on the top of the supporting steel sheet pile (1); S4, grouting each pouring hole (23) on the top plate (21) in sequence, so that each geobag (22) is filled with reinforcement mortar; S5. Then grout the remaining space in the groove and complete the water-blocking support construction after it solidifies.

6. The construction method of the water-blocking support structure in a water-rich soft soil area according to claim 5 is characterized by: The specific grooving method in step S1 is: using a hydraulic grab and a hydraulic double-wheel milling machine for construction, specifically including: S1. Use a hydraulic grab to dig into the sand layer at two locations along the guide wall at appropriate intervals, i.e., dig two side holes; S2. Use hydraulic double-wheel milling to mill the side holes to the final hole depth; S3. Repeat step S1 for the unexcavated area within the central soil range of the two side holes, leaving enough original soil between the central grab excavation hole and the side holes to ensure the stability of the trough and to retain the soil size to facilitate grab milling. S4. Repeat step S3 for the remaining unexcavated area within the two side holes. S5, using a hydraulic double-wheel milling machine to mill the middle hole dug in step S3 and step S4 to the final hole depth; S6. Use a hydraulic grab to dig the original soil remaining in the trench section to the sand layer; S7. After the original soil remaining in the trench section is excavated to the sand layer, a hydraulic double-wheel milling machine is used to mill the remaining original soil to the final hole depth, that is, the trench excavation is completed by multiple trenches.

7. The construction method of the water-blocking support structure in water-rich soft soil area according to claim 6 is characterized by: During the construction process of the hydraulic grab and hydraulic double-wheel milling machine, mud wall protection construction is carried out on the excavated hole, and the mud mix ratio is: water: bentonite: CMC: sodium carbonate: barium sulfate = 1000:2:20:30.

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