Strip wall type underground continuous wall composite anchorage foundation and construction method thereof

Abstract

The present application relates to a kind of strip wall underground continuous wall composite anchorage foundation and its construction method, load is transferred to surrounding soil by shaft type ground wall, lining, main body and strip wall ground wall, strip wall ground wall bottom enters bearing stratum, strip wall ground wall's advantageous load contribution is fully played, can utilize the side resistance advantage provided by the larger lateral area of strip wall ground wall, the safety factor of horizontal cable force will be very high, it is not necessary to excavate deeper to construct larger main body to increase dead weight to improve horizontal bearing capacity, reduce the volume and dead weight of whole anchorage body;It also makes full use of the arch effect self-stabilizing action of shaft type ground wall, under the arch effect self-stabilizing action of shaft type ground wall, the burial depth of shaft type ground wall only needs to meet the safety and stability requirements of main body foundation pit construction, the burial depth of shaft type ground wall does not need to be embedded in rock layer and larger burial depth, which greatly reduces the excavation depth and reduces construction risk, saves engineering cost, effectively solves the problems of foundation pit support safety and anchorage foundation construction.

Description

Technical Field

[0001] This invention relates to the field of bridge foundation technology, and in particular to a strip-wall type underground continuous wall composite anchor foundation and its construction method. Background Technology

[0002] Diaphragm walls are widely used in the anchorage foundations of long-span suspension bridges due to their advantages such as high bearing capacity, high stiffness, good seepage prevention and water stopping effect, quick construction, and applicability to various geological conditions. However, current diaphragm wall anchorage foundations are mainly designed according to gravity-based stability requirements such as anti-slip and anti-overturning, without considering the resistance of the soil on the wall side above the foundation slab, nor the bearing capacity of the diaphragm wall embedded in the bearing layer, which places high demands on the bearing layer of the foundation.

[0003] To meet the requirements for anti-slip, anti-overturning, and foundation bearing capacity, sufficiently large foundation weight and size, as well as sufficiently deep burial depth, are often required. This directly leads to problems such as the construction safety of ultra-large and ultra-deep foundation pits and the large volume of concrete used, which increases construction safety risks and causes significant cost waste.

[0004] For example, the commonly used traditional diaphragm wall anchorage foundations are closed circular, infinity-shaped, rectangular and other closed types. The bottom of the wall needs to penetrate into the rock layer or be reinforced with deep foundation to enter a better bearing layer, resulting in a large excavation depth for the diaphragm wall. Moreover, in the entire design process, the diaphragm wall is only used as a temporary retaining structure and is not considered as the main load-bearing structure. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies, such as the bottom of the diaphragm wall anchor foundation entering the rock layer or the deep foundation reinforcement entering the better bearing layer, resulting in a large excavation depth of the diaphragm wall, and the fact that the diaphragm wall is only used as a temporary retaining structure in the entire design process without being considered as the main load-bearing structure. This invention provides a strip wall type underground continuous wall composite anchor foundation and its construction method.

[0006] In a first aspect, the present invention provides a strip-wall type underground continuous wall composite anchor foundation, comprising:

[0007] A shaft-type diaphragm wall is a circular diaphragm wall with a vertical axis. It is located underground and its top surface connects to the ground.

[0008] The inner lining is fixedly installed along the circumference of the inner wall of the shaft-type diaphragm wall, and the depth of the inner lining is less than the depth of the shaft-type diaphragm wall.

[0009] The main body is located inside the lining and is fixedly connected to the inner wall of the lining.

[0010] Anchor body, which is fixedly connected to the upper part of the main body;

[0011] Strip-wall diaphragm walls are installed along the longitudinal direction of the bridge and are spaced apart along the transverse direction of the bridge. The strip-wall diaphragm walls are installed inside the lining and fixed to the lower part of the main body. The bottom of the strip-wall diaphragm walls enters the bearing layer. The bottom depth of the strip-wall diaphragm walls is greater than the bottom depth of the shaft-type diaphragm walls, and the top depth of the strip-wall diaphragm walls is less than the bottom depth of the shaft-type diaphragm walls.

[0012] In this design, the load is primarily borne by the shaft-type diaphragm wall, lining, main structure, and strip-walled diaphragm wall as a whole. The load is transferred to the surrounding soil through these components. The bottom of the strip-walled diaphragm wall extends into the bearing layer, fully utilizing its advantageous load-bearing capacity. The larger lateral area of ​​the strip-walled diaphragm wall provides lateral resistance, resulting in a high safety factor for the horizontal cable force. Therefore, it eliminates the need for deep excavation and the construction of a larger main structure to increase self-weight and improve horizontal bearing capacity, thus reducing the overall anchorage volume and weight. Furthermore, the arch effect of the shaft-type diaphragm wall is fully utilized for self-stabilization. Under the arch effect of the shaft-type diaphragm wall, the inner side of the shaft-type diaphragm wall... The inner lining serves as the internal support for the foundation pit where the main structure is located, avoiding traditional internal support measures (such as traditional concrete and steel support beams). This eliminates the need for excessive internal support structures. The embedment depth of the shaft-type diaphragm wall only needs to meet the safety and stability requirements of the main foundation pit construction. Specifically, the strip-wall diaphragm wall is fixed to the lower part of the main structure, with the top depth of the strip-wall diaphragm wall being less than the bottom depth of the shaft-type diaphragm wall, and the bottom depth being greater than the bottom depth of the shaft-type diaphragm wall. The embedment depth of the shaft-type diaphragm wall does not need to be embedded in the rock strata or be too deep; it only needs to be sufficient to support the main foundation pit excavation. This greatly reduces the excavation depth and construction risks, saves project costs, and effectively solves the problems of foundation pit support safety and anchor foundation construction.

[0013] Preferably, the main body includes a top plate and a bottom plate;

[0014] The top plate is fixed above the bottom plate, and the anchor body is fixedly connected to the top plate.

[0015] The base plate consists of a first base plate and a second base plate. The first base plate is poured before the second base plate. The top of the first base plate and the second base plate are connected to the top plate. The second base plate is a trumpet-shaped section, with the upper part of the trumpet-shaped section being larger than the lower part. The lower part of the trumpet-shaped section is connected to the upper part of the strip wall-type diaphragm wall.

[0016] The foundation slab consists of a first part and a second part. The first part is poured before the second part to initially separate the foundation slab from the strip-wall diaphragm. After pouring, the first part settles under its own weight, making full contact with the bottom soil. The base soil generates a reaction force, which can share some of the upper load. However, the load above the main structure is large, and the base soil reaction force alone is insufficient. By pouring a funnel-shaped concrete area before the anchor construction, the strip-wall diaphragm is rigidly connected to the foundation slab. At this point, the strip-wall diaphragm plays its role, and the upper structural load can be directly transferred to it. Finally, the base soil reaction force and the strip-wall diaphragm jointly bear the upper load. Even if the foundation soil below the foundation slab is fully consolidated and compacted under the action of the first part of the foundation slab, the bearing capacity of the foundation soil below the foundation slab can be fully utilized, reducing the load that the strip-wall diaphragm needs to bear. This also indirectly reduces the size of the diaphragm wall and the amount of excavation. The use of trumpet-shaped sections, with trumpet-shaped steel cages inside, makes it less prone to slippage; and it enables the first and second parts of the base plate to form better shear support, improving the vertical load-bearing capacity of the base plate after it is formed.

[0017] Preferably, the lower part of the top plate has a tenon and a mortise, which are provided on the side of the lower part of the first part of the top plate above the first part of the bottom plate. The lower part of the first part of the top plate is cast before the second part of the bottom plate.

[0018] The vertical shear capacity of the top slab can be improved by setting a tongue and groove joint. The connection between the strip-wall diaphragm wall and the bottom slab can be constructed after the construction of the first part of the bottom slab and the lower part of the first part of the top slab. This allows the foundation soil below the bottom slab to be fully consolidated and compacted under the self-weight of the first part of the bottom slab and the lower part of the first part of the top slab. This can make full use of the bearing capacity of the foundation soil below the bottom slab, reduce the stress on the diaphragm wall, and indirectly reduce the size of the diaphragm wall.

[0019] Preferably, the clear distance between the edge of the strip-wall type diaphragm wall and the inner edge of the lining is not less than 1m, which facilitates the setting of the trumpet section and avoids interference with the shaft-type diaphragm wall.

[0020] Preferably, the lining is arranged in a stepped manner along the depth, with the lower part of the lining being larger than the upper part. When excavating the main foundation pit, the deeper the pit, the greater the soil pressure. Setting the lower part of the lining to be larger than the upper part in a stepped manner can ensure the load-bearing capacity and can better form vertical support for the main structure after the main construction is completed.

[0021] Preferably, the shaft-type diaphragm wall includes vertical joints, which are milled joints. The depth of the bottom of the shaft-type diaphragm wall is lower than the depth of the bearing layer. The shaft-type diaphragm wall is mainly used for the retaining structure during foundation pit construction. The use of milled joints can reduce construction costs while ensuring load-bearing capacity.

[0022] Preferably, the strip-wall type diaphragm wall is arranged in parallel with equal spacing to effectively reduce the group wall effect.

[0023] Preferably, the wall spacing of the strip-wall diaphragm wall is 6d to 10d, where d is the wall thickness of the strip-wall diaphragm wall. This significantly reduces the group wall effect and allows for a more suitable top slab size for the foundation, thus reducing costs.

[0024] Preferably, the strip-wall type diaphragm wall has a vertical joint, and the vertical joint of the strip-wall type diaphragm wall is a rigid joint, which can better realize vertical load-bearing.

[0025] In a second aspect, the present invention provides a construction method for a strip-wall type diaphragm wall composite anchor foundation, used for constructing the aforementioned strip-wall type diaphragm wall composite anchor foundation, comprising the following steps:

[0026] S1: Construction of shaft-type ground connection wall;

[0027] S2: Construction strip-type diaphragm wall;

[0028] S3: Excavation of the foundation pit inside the shaft-type diaphragm wall and construction of the inner lining, so that the inner lining and the inner wall of the shaft-type diaphragm wall form an integral structure;

[0029] S4: Construct the main body layer by layer from the top of the strip-wall diaphragm and the inside of the lining, so that the main body, the lining, and the strip-wall diaphragm form an integral whole.

[0030] S5: Construct the anchor body at the top of the main structure; construction complete.

[0031] In this scheme, the construction of a shaft-type diaphragm wall provides safety conditions for the construction of a strip-wall diaphragm wall. Both shaft-type and strip-wall diaphragm wall construction provide safety conditions for the excavation of the foundation pit within the shaft-type diaphragm wall and the construction of the inner lining. The inner lining construction ensures safety after the foundation pit excavation. After the foundation pit excavation is completed, the main structure is constructed layer by layer from the top of the strip-wall diaphragm wall and the inner side of the inner lining, forming a unified whole with the inner lining and strip-wall diaphragm wall, thus achieving overall structural integrity. Anchors are constructed at the top of the main structure to connect cables. This construction method ensures the safety of the entire construction process and reduces the scale of the shaft-type diaphragm wall, the foundation pit excavation, and the pouring scale of the main structure. Furthermore, if the strip-wall diaphragm wall is constructed at the bottom of the foundation pit, the water head pressure is high, posing a significant safety risk during trenching and increasing the likelihood of borehole collapse. In this method, the strip-wall diaphragm wall is constructed before the foundation pit excavation, facilitating surface construction and mud treatment. Moreover, the impact of the groundwater level on the stability of the trench wall is minimal, making the construction safer and more reliable.

[0032] Preferably, the steps before step S1 include: leveling the site, and then constructing the guide walls for the shaft-type diaphragm wall and the strip-type diaphragm wall;

[0033] In step S1, the first-phase trench section and the second-phase trench section of the diaphragm wall are constructed to form a closed circular ring-shaped diaphragm wall enclosure structure.

[0034] In step S2, the first-phase trench section and the second-phase trench section of the strip-wall diaphragm wall are constructed to form a parallel strip-wall diaphragm wall structure.

[0035] In step S3, the soil inside the foundation pit of the well-type diaphragm wall is excavated in layers, and the inner lining is constructed using the reverse construction method, so that the inner lining and the well-type diaphragm wall form an integral whole.

[0036] Step S4 includes the following steps:

[0037] S4.1 After excavating to the top of the strip-wall diaphragm wall to form the bottom of the pit, remove the plain concrete in the top area of ​​the strip-wall diaphragm wall and install trumpet-shaped steel bars at the top of the strip-wall diaphragm wall.

[0038] S4.2. Pour the foundation layer and bottom sealing concrete, and then pour the bottom plate part other than the trumpet-shaped steel bars to form the first part of the bottom plate, so that the first part of the bottom plate and the inner lining form an integral whole;

[0039] S4.3. Pour the top plate portion above the first bottom plate to 4m-6m below the top surface of the top plate to form the lower part of the first top plate, and make the lower part of the first top plate and the inner lining form an integral whole;

[0040] S4.4. The trumpet-shaped steel bars at the top of the cast-in-place strip-wall diaphragm wall correspond to the bottom slab portion to form a second part of the bottom slab, thus forming a complete bottom slab;

[0041] S4.5. Pour the top slab above the second part of the bottom slab to 4m-6m below the top surface of the top slab to form the lower part of the second part of the top slab, thus forming the lower part of the top slab;

[0042] S4.6. Pour the remaining top slab portion to form the upper part of the top slab, thereby forming a complete top slab, and making the strip-walled diaphragm wall, bottom slab, top slab and lining an integral whole;

[0043] In step S5, the anchor blocks and cable saddle supports are poured in layers and sections.

[0044] In the above construction method, the second part of the base plate is the part that connects the base plate to the strip-wall diaphragm. The lower part of the first part of the base plate and the first part of the top plate are poured before the second part of the base plate. This can make full use of the self-weight of the lower part of the first part of the base plate and the first part of the top plate to fully consolidate and compact the foundation soil below the base plate. This can make full use of the bearing capacity of the foundation soil below the base plate, reduce the stress on the diaphragm wall, and indirectly reduce the size of the diaphragm wall, making the strip-wall diaphragm wall in step S2 smaller and reducing the construction difficulty.

[0045] Preferably, in step S4.4, the lower part of the first part of the top plate is provided with a tenon and mortise on the side facing the strip-wall type ground diaphragm.

[0046] The tongue and groove joint can effectively connect the lower part of the first part of the top plate and the lower part of the second part of the top plate to form a vertical shear load-bearing structure, forming an integral lower part of the top plate and improving the overall load-bearing capacity of the top plate.

[0047] Preferably, when constructing the top slab, construction is carried out layer by layer from bottom to top, with cooling pipes arranged in each layer of the top slab and anchor steel bars pre-embedded.

[0048] This ensures the quality of the roof slab construction.

[0049] Preferably, in step S2, the strip-wall type diaphragm wall in the middle part is constructed first, and then the strip-wall type diaphragm walls on both sides are constructed.

[0050] The length of the middle strip-type diaphragm wall is greater than that of the two side strip-type diaphragm walls. Constructing the longer strip-type diaphragm wall first can reduce the disturbance to the construction of the subsequent strip-type diaphragm walls, resulting in better construction quality.

[0051] Preferably, in step S1, before excavating the guide walls on both sides of the shaft-type diaphragm wall and the strip-wall type diaphragm wall, the trench walls on both sides of the shaft-type diaphragm wall and the strip-wall type diaphragm wall are reinforced, which can improve the safety and construction quality of the shaft-type diaphragm wall and the strip-wall type diaphragm wall construction.

[0052] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0053] 1. This invention provides a strip-wall type diaphragm wall composite anchorage foundation. Through a shaft-type diaphragm wall, lining, main body, and strip-wall type diaphragm wall, the load is transferred to the surrounding soil. The bottom of the strip-wall type diaphragm wall enters the bearing layer, fully utilizing its advantageous bearing capacity contribution. It leverages the lateral resistance advantage provided by the larger lateral area of ​​the strip-wall type diaphragm wall, resulting in a high safety factor for horizontal cable force. Therefore, it eliminates the need for deep excavation and the construction of a larger main body to increase self-weight and improve horizontal bearing capacity, reducing the overall anchorage volume and self-weight. Furthermore, it fully utilizes the shaft-type... The arch effect of the diaphragm wall provides self-stabilization. Under the arch effect of the shaft-type diaphragm wall, an inner lining is set on the inside of the shaft-type diaphragm wall as the internal support of the foundation pit where the main body is located. It is not necessary to set up too many internal support structures. The burial depth of the shaft-type diaphragm wall only needs to meet the safety and stability requirements of the main foundation pit construction. The burial depth of the shaft-type diaphragm wall does not need to be embedded in the rock layer or be too deep. It is enough to achieve the protection of the main foundation pit excavation. This greatly reduces the excavation depth and construction risks, saves project costs, and effectively solves the problems of foundation pit support safety and anchor foundation construction.

[0054] 2. This invention provides a construction method for a strip-wall type underground continuous wall composite anchor foundation. The construction of the shaft-type diaphragm wall provides safety conditions for the construction of the strip-wall type diaphragm wall. The shaft-type diaphragm wall construction and the strip-wall type diaphragm wall construction provide safety conditions for the excavation of the foundation pit and the construction of the inner lining within the shaft-type diaphragm wall. The inner lining construction ensures safety after the foundation pit excavation. After the foundation pit excavation is completed, the main structure is constructed layer by layer upwards from the top of the strip-wall type diaphragm wall and the inner side of the inner lining, so that the main structure, the inner lining, and the strip-wall type diaphragm wall form an integral whole, forming a unified load-bearing structure. Anchor bodies are constructed at the top of the main structure for connecting cables. This construction method can ensure the safety of the entire construction process and can reduce the excavation scale of the shaft-type diaphragm wall and the foundation pit, as well as the pouring scale of the main structure. Attached Figure Description

[0055] Figure 1 This is a side view of a strip-wall type diaphragm wall composite anchor foundation;

[0056] Figure 2 for Figure 1 A schematic diagram of the viewpoint at point AA in the middle;

[0057] Figure 3 for Figure 1 A schematic diagram of the viewpoint at point BB in the middle;

[0058] Figure 4 This is a side view of the diaphragm wall;

[0059] Figure 5 for Figure 4 A schematic diagram of the viewpoint at the center CC;

[0060] Figure 6 for Figure 4 A schematic diagram of the viewpoint at point DD;

[0061] Figure 7 This is a schematic diagram showing the setup of the first and second base plates.

[0062] Figure 8 This is a schematic diagram showing the arrangement of the lower part of the first part of the top plate and the lower part of the second part of the top plate;

[0063] Figure 9 This is a schematic diagram showing the excavation of the foundation pit to the bottom.

[0064] Figure 10 This is a schematic diagram showing the first part of the base slab after it has been poured.

[0065] Figure 11 A schematic diagram showing the protrusions and recesses on the lower side of the first part of the top plate;

[0066] Figure 12 This is a schematic diagram showing the lower part of the second-part base plate, the lower part of the second-part top plate, and the upper part of the top plate.

[0067] Figure 13 A side view of the reinforcement using mixing piles;

[0068] Figure 14 A schematic diagram of reinforcement using mixing piles;

[0069] Figure 15 This is a side view of the construction guide wall;

[0070] Figure 16 This is a plan view of the construction guide wall;

[0071] Figure 17 This is a side view of the excavated trench section;

[0072] Figure 18 This is a plan view of the excavated trench section;

[0073] Figure 19 This is a side view of the first unit wall under construction;

[0074] Figure 20 This is a plan view of the first unit wall under construction;

[0075] Figure 21 This is a side view diagram after the construction of the shaft-type diaphragm wall;

[0076] Figure 22 This is a plan view of the diaphragm wall after construction of the shaft type;

[0077] Figure 23 This is a side view diagram after the construction of the first strip-type diaphragm wall;

[0078] Figure 24 This is a plan view after the construction of the first strip-wall diaphragm wall;

[0079] Figure 25 A side view diagram after the construction of all strip-wall diaphragm walls;

[0080] Figure 26 A plan view showing the completed construction of all strip-wall diaphragm walls;

[0081] Figure 27 A side view of the beam cap for excavating the foundation pit and constructing the top of the inner lining;

[0082] Figure 28 A plan view of the beam cap for excavating the foundation pit and constructing the top of the inner lining;

[0083] Figure 29 A side view of the excavated foundation pit after the inner lining has been constructed;

[0084] Figure 30 This is a plan view of the excavated foundation pit after the inner lining has been constructed.

[0085] Figure 31 This is a side view diagram after the base plate has been installed;

[0086] Figure 32 This is a plan view of the area after the foundation slab has been constructed;

[0087] Figure 33 This is a side view diagram after the construction of the roof slab;

[0088] Figure 34 This is a plan view after the construction of the roof slab;

[0089] Figure 35 This is a side view of the anchor body after construction;

[0090] Figure 36 This is a plan view of the anchor body after construction.

[0091] Marked in the image:

[0092] 1. Well-type diaphragm wall; 2. Lining; 21. Excavation pit; 3. Anchor body; 4. Strip-wall type diaphragm wall; 5. Bottom slab; 51. First part of bottom slab; 52. Second part of bottom slab; 6. Top slab; 61. Lower part of the first part of top slab; 61. Tenon and groove; 62. Lower part of the second part of top slab; 63. Upper part of top slab; 7. Mixing pile; 71. Rear anchor face; 72. Cable saddle; 8. Side ditch; 91. Guide wall; 92. Trench wall; 93. First unit trench section; 94. Guide ditch; 95. First unit wall; 96. First strip-wall type diaphragm wall; 97. Beam cap. Detailed Implementation

[0093] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0094] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0095] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0096] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing between identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0097] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0098] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set", "install", "connect", "link", "provided with", "lay out", and "arrange" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections, and can refer to connection methods commonly used in the art, such as welding, riveting, bolting, and threaded connections.

[0099] Example 1

[0100] like Figure 1-6 As shown, a strip-wall type diaphragm wall composite anchor foundation includes a shaft-type diaphragm wall 1, an inner lining 2, a main body, an anchor body 3, and a strip-wall type diaphragm wall 4.

[0101] like Figure 3 and Figure 6 As shown, the shaft-type diaphragm wall 1 is circular, as follows: Figure 1 As shown, the shaft-type diaphragm wall 1 is vertical in axis, located underground, and its top surface is connected to the ground.

[0102] In some embodiments, the shaft-type diaphragm wall 1 includes a vertical joint, which is a milled joint. The depth of the bottom of the shaft-type diaphragm wall 1 is lower than the depth of the bearing layer. The shaft-type diaphragm wall 1 is mainly used for the retaining structure during the construction of the foundation pit 21. The use of a milled joint can reduce construction costs while ensuring load-bearing capacity. Of course, the shaft-type diaphragm wall 1 can also use a vertical rigid joint.

[0103] like Figure 3 and Figure 6 As shown, the inner lining 2 is fixedly installed circumferentially along the inner wall of the shaft-type diaphragm wall 1, as follows: Figure 1 As shown, the bottom depth of the inner lining 2 is less than the depth of the shaft-type diaphragm wall 1; the inner lining 2 serves as an internal support for the foundation pit 21, and also bears the load together with the main structure after the main structure is constructed;

[0104] like Figures 1-3 As shown, the main body is located inside the inner lining 2 and is fixedly connected to the inner wall of the inner lining 2;

[0105] like Figures 1-3 As shown, the anchor body 3 is fixedly connected to the upper part of the main body, and the anchor body 3 is used to connect the cable;

[0106] The strip-wall type diaphragm wall 4 is installed along the direction of the bridge. Figure 1 The left and right directions are along the bridge direction; the strip-wall type diaphragm walls are distributed at intervals along the transverse direction of the bridge. Figure 2 The left and right directions are transverse bridge directions; the strip-wall type diaphragm wall 4 is set inside the inner lining 2 and fixed to the lower part of the main body. The bottom of the strip-wall type diaphragm wall 4 enters the bearing layer. The bearing layer can be a stable stratum or a rock stratum that can provide a large anchoring force. The bottom depth of the strip-wall type diaphragm wall 4 is greater than the bottom depth of the shaft type diaphragm wall 1, and the top depth of the strip-wall type diaphragm wall 4 is less than the bottom depth of the shaft type diaphragm wall 1.

[0107] The aforementioned strip-wall type diaphragm wall composite anchorage foundation structure is mainly supported by the shaft-type diaphragm wall 1, the inner lining 2, the main body, and the strip-wall type diaphragm wall 4 as a whole. The load of the anchor body 3 acts on the top slab 6, which transfers the load to the bottom slab 5. The bottom slab 5 then transfers the load to the strip-wall type diaphragm wall 4 and the foundation soil below the bottom slab 5, and finally to the bearing layer via the strip-wall type diaphragm wall 4. In other words, the strip-wall type diaphragm wall 4 and the foundation soil below the bottom slab 5 jointly bear the vertical load. The anchor body 3 is pulled by the anchor cable, producing... A horizontal load is generated, which acts on the top slab 6. The top slab 6 transmits the load to the bottom slab 5 and the inner lining 2. The bottom slab 5 acts on the strip-walled diaphragm wall 4 and the inner lining 2. The load is then transmitted from the inner lining 2 to the shaft-type diaphragm wall 1. The shaft-type diaphragm wall 1 and the strip-walled diaphragm wall 4 share the horizontal load, but the main horizontal load is shared by the strip-walled diaphragm wall 4. The strip-walled diaphragm wall 4 has a large area in the longitudinal direction of the bridge, which can generate friction with the foundation soil, thereby forming frictional resistance to resist the tension of the anchor cable.

[0108] This method transfers the load to the surrounding soil through the shaft-type diaphragm wall 1, the inner lining 2, the main body, and the strip-walled diaphragm wall 4. The bottom of the strip-walled diaphragm wall 4 enters the bearing layer, fully utilizing its advantageous bearing capacity. The large lateral area of ​​the strip-walled diaphragm wall 4 provides lateral resistance, resulting in a high safety factor for the horizontal cable force. Therefore, it eliminates the need for deep excavation and the construction of a larger main body to increase self-weight and improve horizontal bearing capacity, thus reducing the overall anchorage volume and self-weight. Furthermore, it fully utilizes the arch effect self-stabilizing effect of the shaft-type diaphragm wall 1. Under the arch effect self-stabilizing effect of the shaft-type diaphragm wall 1, the inner lining 2 is installed inside the shaft-type diaphragm wall 1 as an internal support for the foundation pit 21 where the main body is located. This design avoids traditional internal support measures (such as traditional concrete and steel internal support beams), eliminating the need for excessive internal support structures. The burial depth of the shaft-type diaphragm wall 1 only needs to meet the safety and stability requirements of the main foundation pit 21 construction. That is, the strip-wall type diaphragm wall 4 is fixed to the lower part of the main structure, with the top depth of the strip-wall type diaphragm wall 4 being less than the bottom depth of the shaft-type diaphragm wall 1 and the bottom depth of the strip-wall type diaphragm wall 4 being greater than the bottom depth of the shaft-type diaphragm wall 1. The burial depth of the shaft-type diaphragm wall 1 does not need to be embedded in the rock layer or have a large burial depth. It is sufficient to achieve the enclosure of the main foundation pit 21 excavation. This greatly reduces the excavation depth and construction risks, saves project costs, and effectively solves the problems of foundation pit 21 support safety and anchor foundation construction.

[0109] In some embodiments, such as Figure 7 As shown, the main body includes a top plate 6 and a bottom plate 5;

[0110] The top plate 6 is fixed above the bottom plate 5, and the anchor 3 is fixedly connected above the top plate 6;

[0111] The base plate 5 includes a first part base plate 51 and a second part base plate 52. The first part base plate 51 is poured before the second part base plate 52. The top of the first part base plate 51 and the second part base plate 52 are connected to the top plate 6. The second part base plate 52 is a trumpet segment, with the upper part of the trumpet segment being larger than the lower part. The lower part of the trumpet segment is connected to the upper part of the strip wall diaphragm 4.

[0112] The base plate 5 includes a first part, base plate 51, and a second part, base plate 52, as follows: Figure 10 and Figure 12As shown, the first part of the base slab 51 is poured before the second part of the base slab 52. The purpose is to ensure that the base slab 5 is not initially connected to the strip-wall diaphragm wall 4. After the first part of the base slab 51 is poured, it settles under its own weight, making full contact with the soil below the base slab 5. The base soil generates a reaction force, which can share part of the upper load. However, the load above the main structure is large, and the soil reaction force of the base alone cannot meet the requirements. By pouring the funnel-shaped area concrete before the construction of the anchor body 3, the strip-wall diaphragm wall 4 is rigidly connected to the base slab 5. At this time, the strip-wall diaphragm wall 4 plays its role, and the upper structural load can be directly transferred to the strip-wall diaphragm wall 4. Finally, the base soil reaction force and the strip-wall diaphragm wall 4 jointly bear the upper load. Even if the foundation soil below the base slab 5 is fully consolidated and compacted under the action of the first part of the base slab 51, the bearing capacity of the foundation soil below the base slab 5 can be fully utilized, which can reduce the load required for the strip-wall diaphragm wall 4. This can also indirectly reduce the size of the diaphragm wall and reduce the amount of excavation.

[0113] Furthermore, such as Figure 8 As shown, the top plate 6 includes the upper part of the top plate 63 and the lower part of the top plate 6. The lower part of the top plate 6 includes a first part of the lower top plate 61 and a second part of the lower top plate 62. The first part of the lower top plate 61 is located above the first part of the bottom plate 51, and the second part of the lower top plate 62 is located above the second part of the bottom plate 52.

[0114] like Figures 10-12 As shown, the construction of the connection between the strip-walled diaphragm wall 4 and the base slab 5 (i.e., the construction of the second part of the base slab 52) can be carried out after the construction of the first part of the base slab 51 and the lower part of the first part of the top slab 61. This allows the foundation soil below the base slab 5 to be fully consolidated and compacted under the self-weight of the first part of the base slab 51 and the lower part of the first part of the top slab 61, thus fully utilizing the bearing capacity of the foundation soil below the base slab 5, reducing the stress on the diaphragm wall, and further reducing the size of the diaphragm wall. Assuming that, according to conventional practices, the load-bearing ratio of the foundation soil reaction is 10%, and the strip-walled diaphragm wall 4 bears 90% of the load; with this construction method, the foundation reaction can reach about 30%, while the strip-walled diaphragm wall 4 bears 70% of the load. Therefore, it is not necessary to design such a large-scale diaphragm wall (e.g., reducing the depth of the diaphragm wall by a few meters or reducing its length along the bridge direction by a few meters) to meet the design requirements.

[0115] Furthermore, the lower part 61 of the first top plate has a tongue and groove tenon 611 on its side. After the lower part 62 of the second top plate is poured, a tongue and groove fit can be formed, thereby forming a vertical shear load-bearing capacity and ensuring the load-bearing capacity of the lower part of the top plate 6. In addition, longitudinal and transverse steel bars are provided at the tongue and groove tenon 611 of the lower part 62 of the second top plate and the lower part 61 of the first top plate for connection and fixation.

[0116] Furthermore, a trumpet-shaped section, wider at the top and narrower at the bottom, is designed. Before constructing the first part of the base slab 51, the trumpet-shaped steel reinforcement cage for the trumpet-shaped section will be installed first. To avoid interference between the trumpet-shaped steel reinforcement cage and the shaft-type diaphragm wall 1, the clear distance between the edge of the strip-wall type diaphragm wall 4 and the inner edge of the inner lining 2 is not less than 1m, facilitating the installation of the trumpet-shaped section. For example... Figure 6 As shown, from the side to the middle, the lengths of the strip-wall type diaphragm wall 4 are 40m, 67m, 70m, 78m and 81m respectively, and the end of the 81m strip-wall type diaphragm wall 4 is about 3m away from the shaft type diaphragm wall 1.

[0117] In some embodiments, such as Figure 1 As shown, when excavating the main foundation pit 21, the deeper the depth, the greater the soil pressure. The lower part of the inner lining 2 is set as a stepped shape with the upper part larger than the lower part. That is, the inner lining 2 is arranged in a stepped shape along the depth, with the lower part of the inner lining 2 being larger than the upper part. This can ensure the load-bearing capacity and can better form vertical support for the main body after the main construction is completed in the later stage.

[0118] In some embodiments, such as Figure 3 and Figure 6 As shown, the strip-type diaphragm walls 4 are arranged in parallel at equal intervals, such as... Figure 6 As shown, the spacing is 'a', effectively reducing the wall cluster effect. Furthermore, the wall spacing of the strip-wall diaphragm wall 4 is 6d to 10d, where 'd' is the wall thickness of the strip-wall diaphragm wall 4. This significantly reduces the wall cluster effect, and the scale of the foundation's top slab 6 is appropriate, reducing costs. In this embodiment, when the strip-wall diaphragm wall 4 is long, it needs to be constructed in two phases: a first-phase trench section and a second-phase trench section. Therefore, the strip-wall diaphragm wall 4 has vertical joints. These vertical joints are rigid joints, located between the first-phase and second-phase trench sections, which better achieves vertical load-bearing capacity.

[0119] Extensive calculations and studies have shown that during the normal operation of the anchor foundation, the retaining diaphragm wall bears a significant proportion of the load. To fully utilize the load-bearing capacity of the diaphragm wall, this embodiment proposes a strip-wall type diaphragm wall composite anchor foundation. The load of the strip-wall type diaphragm wall composite anchor foundation is mainly borne by the shaft-type diaphragm wall 1, top slab 6, bottom slab 5, inner lining 2, and the lower sheet-like strip-wall type diaphragm wall 4. The load is transferred to the surrounding soil through the shaft-type diaphragm wall 1, inner lining 2, top slab 6, bottom slab 5, and strip-wall type diaphragm wall 4. This fully utilizes the advantageous load-bearing contribution of the strip-wall type diaphragm wall 4, while also fully utilizing the arch effect self-stabilizing effect of the shaft-type diaphragm wall 1. The burial depth of the shaft-type diaphragm wall 1 only needs to meet the construction safety and stability requirements of the foundation pit 21 of the bottom slab 5 and top slab 6, without needing to be embedded in the rock strata or have a large burial depth. Furthermore, the connection between the strip-wall diaphragm wall 4 and the base slab 5 can be constructed after the base slab 5 and a portion of the top slab 6 have been built. This allows the foundation soil below the base slab 5 to be fully consolidated and compacted under the self-weight of the constructed base slab 5 and top slab 6, thus fully utilizing the bearing capacity of the foundation soil below the base slab 5 and reducing the stress on the diaphragm wall. This also indirectly reduces the size of the diaphragm wall. Therefore, the strip-wall diaphragm wall composite anchor foundation of this embodiment can greatly reduce the foundation excavation depth and construction risk, while also shortening the construction period and reducing environmental impact. It is suitable for various geological conditions, has significant economic and environmental benefits, and has broad application prospects.

[0120] Example 2

[0121] A construction method for a strip-wall type diaphragm wall composite anchor foundation, used for constructing any of the strip-wall type diaphragm wall composite anchor foundations described in Example 1, includes the following steps:

[0122] S1: As Figure 21 As shown, a shaft-type diaphragm wall 1 is constructed; the construction of the shaft-type diaphragm wall 1 can be carried out using the conventional diaphragm wall construction method.

[0123] Furthermore, such as Figures 13-16 As shown, the steps before step S1 include: leveling the site, and then constructing the guide wall 91 of the shaft-type diaphragm wall 1 and the strip-wall type diaphragm wall 4;

[0124] Furthermore, in step S1, as Figure 13 and Figure 14 As shown, before excavating the guide walls 91 on both sides of the shaft-type diaphragm wall 1 and the strip-wall type diaphragm wall 4, the trench walls 92 on both sides of the shaft-type diaphragm wall 1 and the strip-wall type diaphragm wall 4 are reinforced, which can improve the safety and construction quality of the shaft-type diaphragm wall 1 and the strip-wall type diaphragm wall 4.

[0125] Furthermore, such as Figure 21As shown, in step S1, the first-phase trench section and the second-phase trench section diaphragm wall 1 of the construction shaft-type diaphragm wall 1 are constructed to form a closed circular shaft-type diaphragm wall 1 enclosure structure; a milling joint is used between the first-phase trench section and the second-phase trench section diaphragm wall.

[0126] S2: As Figure 25 and Figure 26 As shown, the construction of the strip-type diaphragm wall 4 is carried out; the construction of the strip-type diaphragm wall 4 can be carried out in the conventional diaphragm wall construction method.

[0127] Furthermore, in step S2, the first-phase trench section and the second-phase trench section of the strip-wall diaphragm wall 4 are constructed to form a parallel strip-wall diaphragm wall 4 structure.

[0128] Furthermore, in step S2, as Figure 24 and Figure 26 As shown, the strip-type diaphragm wall 4 in the middle part is constructed first, and then the strip-type diaphragm walls 4 on both sides are constructed.

[0129] The length of the middle strip-type diaphragm wall 4 is greater than that of the two side strip-type diaphragm walls 4. Constructing the longer strip-type diaphragm wall 4 first can reduce the disturbance to the subsequent construction of the strip-type diaphragm wall 4, resulting in better construction quality.

[0130] Post-grouting measures are adopted on both the sides and bottom of the wall to improve the frictional resistance on the sides and the resistance at the bottom of the wall.

[0131] For the connection between the first and second phase diaphragm wall sections, rigid joints should be used. The length of the diaphragm section should be appropriately increased to reduce the number of vertical joints. For example, a 50m long diaphragm wall consists of a 50m long diaphragm section. In actual construction, the 50m is divided into many sections for construction and casting. Vertical joints are left between adjacent sections. If each section is 5m long, there are 10 diaphragm sections and 9 vertical joints; if each section is 10m long, there are 5 diaphragm sections and 4 vertical joints. The first and second phase diaphragm sections are along the length of the diaphragm wall.

[0132] S3: As Figure 29 and Figure 30 As shown, the foundation pit 21 inside the shaft-type diaphragm wall 1 is excavated and the inner lining 2 is constructed, so that the inner lining 2 and the inner wall of the shaft-type diaphragm wall 1 form an integral structure; wherein, the inner lining 2 is constructed simultaneously during the excavation of the foundation pit 21, and the inner lining 2 adopts a reinforced concrete structure.

[0133] Furthermore, in step S3, the soil inside the foundation pit 21 inside the shaft-type diaphragm wall 1 is excavated in layers, and the inner lining 2 is constructed using the reverse construction method, so that the inner lining 2 and the shaft-type diaphragm wall 1 form an integral whole.

[0134] S4: As Figures 31-34As shown, the main body is constructed layer by layer from the top of the strip-wall diaphragm 4 and the inner side of the inner lining 2, so that the main body, the inner lining 2, and the strip-wall diaphragm 4 form an integral whole.

[0135] S5: As Figures 35-36 As shown, anchor body 3 is constructed at the top of the main structure, and construction is complete. In step S5, anchor blocks and cable saddles 72 are poured in layers and sections.

[0136] In this scheme, the construction of the shaft-type diaphragm wall 1 provides safety conditions for the construction of the strip-wall type diaphragm wall 4. The construction of the shaft-type diaphragm wall 1 and the strip-wall type diaphragm wall 4 provides safety conditions for the excavation of the foundation pit 21 inside the shaft-type diaphragm wall 1 and the construction of the inner lining 2. The construction of the inner lining 2 ensures the safety of the foundation pit 21 after excavation. After the foundation pit 21 is excavated, the main body is constructed layer by layer from the top of the strip-wall type diaphragm wall 4 and the inner side of the inner lining 2, so that the main body, the inner lining 2, and the strip-wall type diaphragm wall 4 form an integral whole and form an integral force. Anchor body 3 is constructed at the top of the main body for connecting cables. This construction method can ensure the safety of the entire construction process and can reduce the excavation scale of the shaft-type diaphragm wall 1 and the foundation pit 21 and the pouring scale of the main structure.

[0137] In some embodiments, step S4 includes the following steps:

[0138] S4.1 After excavating to the top of the strip-walled diaphragm wall 4 to form the bottom of the pit, as follows: Figure 9 As shown, the inner lining 2 has been poured at this point; the plain concrete at the top of the strip-wall diaphragm wall 4 is removed, and trumpet-shaped reinforcing bars are installed at the top of the strip-wall diaphragm wall 4, as shown. Figure 10 As shown, the trumpet-shaped steel bar corresponds to the second part of the bottom slab 52 to be poured;

[0139] S4.2, pour the foundation layer and bottom sealing concrete, then pour the bottom slab 5 parts other than the trumpet-shaped reinforcement to form the first part of the bottom slab 51, as follows. Figure 10 As shown, the first part of the base plate 51 and the inner lining 2 form an integral whole; the cushion layer can be a crushed stone layer, etc. By setting the crushed stone layer and then constructing the bottom sealing concrete, the direct pouring of the base plate 5 will prevent the soil below the base plate 5 from turning up, thus reducing the impact on the pouring quality of the base plate 5; after the first part of the base plate 51 is poured, the first part of the base plate 51 is not connected to the strip wall diaphragm wall 4, and the soil below is the base soil, which can squeeze the soil below the base plate 5, so that the base soil forms a reaction force;

[0140] S4.3, pour the top slab 6 above the first part of the base slab 51 to a depth of 4m-6m below the top surface of the top slab 6 to form the lower part 61 of the first part of the top slab. For example, the top 5m is considered the upper part of the top slab. Figure 11As shown, the lower part 61 of the first top plate forms an integral part with the inner lining 2; at this time, the first part bottom plate 51 is still not connected to the strip wall 4, so the lower part 61 of the first top plate and the first part bottom plate 51 can squeeze the foundation soil below the bottom plate 5 together, so that the foundation soil forms a greater reaction force.

[0141] S4.4, The trumpet-shaped reinforcing bars at the top of the cast-in-place strip-wall diaphragm 4 correspond to the bottom slab 5 to form the second part of the bottom slab 52, as shown. Figure 12 As shown, this forms a complete base plate 5;

[0142] Furthermore, in step S4.4, a tenon 611 is provided on the side of the first part of the lower top plate 61 that faces the strip-wall diaphragm 4 horizontally. The tenon 611 can effectively combine the first part of the lower top plate 61 and the second part of the lower top plate 62 to form a vertical shear bearing, forming an integral lower structure of the top plate 6, thereby improving the overall load-bearing capacity of the top plate 6.

[0143] S4.5, pour the top slab 6 above the second part of the bottom slab 52 to a depth of 4m-6m below the top surface of the top slab 6 to form the lower part 62 of the second part of the top slab, such as... Figure 12 As shown, this forms the lower part of the top plate 6;

[0144] S4.6, Pour the remaining 6 parts of the top slab to form the upper part 63 of the top slab, as shown. Figure 12 As shown, this forms a complete top slab 6, and makes the strip-walled diaphragm wall 4, bottom slab 5, top slab 6 and inner lining 2 form an integral whole;

[0145] In the above construction method, the second part of the base plate 52 is the part connecting the base plate 5 and the strip-wall diaphragm wall 4. The first part of the base plate 51 and the lower part of the first part of the top plate 61 are poured before the second part of the base plate 52. This allows the self-weight of the first part of the base plate 51 and the lower part of the first part of the top plate 61 to fully consolidate and compact the foundation soil below the base plate 5. This allows the bearing capacity of the foundation soil below the base plate 5 to be fully utilized, reducing the stress on the diaphragm wall. This also indirectly reduces the size of the diaphragm wall, making the strip-wall diaphragm wall 4 in step S2 smaller and reducing the construction difficulty. The connection between the base plate and the strip-wall diaphragm wall 4 is rigid. The lining is a cast-in-place lining structure, which is part of the anchor foundation structure and serves as internal support during excavation. The top plate of this invention is a cast-in-place solid structure, which is bonded to the lining during pouring, together forming part of the anchor foundation.

[0146] In the above scheme, when constructing the top slab 6, construction is carried out layer by layer from bottom to top, with cooling pipes arranged layer by layer within the top slab 6, and anchor reinforcement bars pre-embedded. This ensures the construction quality of the top slab 6.

[0147] Regarding the possible construction methods mentioned above, this embodiment provides a specific implementation method for reference:

[0148] I. Leveling the Site: 1. Level the site, smoothing out any uneven areas to the designed ground elevation. 2. Compact the surface soil of the work area.

[0149] II. Constructing side ditches 8 and construction platforms, and constructing mixing piles 7 as follows. Figure 13 and Figure 14 As shown, 1. Construction layout, construction of side ditch 8 and construction platform plan (not shown in the figure). 2. The two sides of the diaphragm wall (well-type diaphragm wall 1 and well-wall type diaphragm wall) are reinforced with mixing piles (or jet grouting piles).

[0150] III. Dig a guide trench 94 and construct a guide wall 91 as follows: Figure 15 and Figure 16 As shown, 1. Survey and set out the diaphragm walls (shaft-type diaphragm wall 1 and shaft-wall type diaphragm wall), and excavate the guide wall 91 trenches for shaft-type diaphragm wall 1 and shaft-wall type diaphragm wall (mixing piles are not shown). 2. Tie the reinforcing steel of the guide wall 91 and erect the formwork, pour concrete and cure it. 3. Remove the formwork and set up wooden supports between the two guide walls 91.

[0151] IV. Construction of the trench for the shaft-type diaphragm wall, as follows: Figure 17 and Figure 18 As shown, 1. Based on the division of unit trench sections, construct the first unit trench section 93. 2. Continue construction and replenish mud until the design elevation is reached.

[0152] 5. Clean the bottom, lower the reinforcing cage, and pour concrete as follows: Figure 19 and Figure 20 As shown, 1. The trench is mechanically moved to remove the sediment from the base. 2. The reinforcing cage is hoisted and placed into the trench. 3. The underwater concrete for the diaphragm wall is poured to form the first unit wall 95 of the well-type diaphragm wall 1.

[0153] VI. Proceed with the construction of the remaining units of the shaft-type diaphragm wall as follows: Figure 21 and Figure 22 As shown, 1. Repeat steps four and five until the construction of the shaft-type diaphragm wall is completed. 2. The shaft-type diaphragm wall 1 is constructed in sections, namely Phase I and Phase II trench segments. 3. After the strength of the two Phase I trench segments reaches 80%, the intermediate Phase II trench segment is constructed. 4. Milling joints are used between the Phase I and Phase II trench segments.

[0154] VII. Construction of Strip-Walled Diaphragm Wall 4 Figure 23 and Figure 24 As shown, 1. The first strip-type diaphragm wall 96 is constructed in the middle, with the top elevation of the wall slightly higher than the bottom elevation of the base slab 5. 2. Backfill the cavity section from the top of the wall to the ground surface with soil.

[0155] 8. Proceed with the construction of the remaining strip-wall type diaphragm wall 4 in sequence, as follows: Figure 25 and Figure 26As shown, 1. Construct other strip-wall type diaphragm walls 4 from the middle outwards. 2. The strip-wall type diaphragm walls 4 are constructed in sections according to Phase I and Phase II trench segments. 3. Rigid joints are used between the walls of Phase I and Phase II trench segments.

[0156] 9. Excavation of foundation pit 21, construction of inner lining 2 as follows Figure 27 and Figure 28 As shown, 1. Excavate the soil inside the foundation pit 21 in layers according to the design requirements, and construct the continuous wall lining 2 using the reverse construction method. 2. Continue excavation after the poured lining 2 has reached the specified strength, and then construct the next layer of lining 2 until it reaches 0.5m above the design elevation. The excavation of foundation pit 21 needs to be carried out in sections, and the lining 2 should be poured within 36 hours of excavating each section. Figure 27 First, construct the inner lining 2 to form the beam cap 97.

[0157] 10. Construction of the top of the strip-type diaphragm wall as follows: Figure 29 and Figure 30 As shown, 1. Remove the top concrete of the strip-wall diaphragm wall 4, which is 5 meters above the bottom elevation of the base slab. 2. Cut off the excess upper reinforcement cage. 3. The top reinforcement cage is set in a trumpet shape.

[0158] 11. Pour the foundation concrete, and construct the base slab as shown in Figure 5. Figure 31 and Figure 32 As shown, 1. Continue excavation manually until the design elevation is reached. 2. Foundation treatment. 3. Pour the foundation layer and bottom sealing concrete. 4. Construct the base slab. 5.

[0159] 12. Construction of the roof slab, 6 as shown Figure 33 and Figure 34 As shown, 1. Arrange the cooling pipes in each layer of the top slab 6 and pre-embed the reinforcing steel bars of the anchor body 3. 2. Pour the foundation top slab 6 in sections and layers.

[0160] The construction of the bottom slab 5 and the top slab 6 can be carried out using steps S4.1-S4.6.

[0161] Thirteen, the structure of the construction anchor body 3 is as follows: Figure 35 and Figure 36 As shown, 1. The anchor blocks and cable saddles 72 are poured in layers and sections to form the rear anchor face 71. 2. Construction of the front anchor chamber floor slab and side walls. 3. Tensioning the anchor blocks, installing the main cable strand anchorage connection components, erecting the cable saddles 72, and installing the main cable strands. 4. Construction of the front anchor chamber and dismantling of the supports.

[0162] This invention features an anchor foundation with high overall rigidity and good stability. It can fully utilize the self-stabilizing capacity of the well-type diaphragm wall arch effect, reduce internal support measures, and enable large-area dry-operation foundation pit construction. At the same time, it can also make full use of the load-bearing capacity of the strip-wall type diaphragm wall. It is well-suited for geological conditions with deep rock strata burial, and overcomes the disadvantage of high cost of traditional diaphragm wall anchor foundations that require excavation to the rock surface. It has the advantages of small excavation volume, safe and convenient construction, short construction period, and low cost. It is a new type of foundation that combines safety, economy, and green environmental protection, and has a promising prospect for engineering applications.

[0163] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A strip-wall type diaphragm wall composite anchor foundation, characterized in that, This includes a shaft-type diaphragm wall, which is circular in shape, with a vertical axis, located underground, and its top surface connected to the ground. The inner lining is fixedly installed circumferentially along the inner wall of the diaphragm wall of the well shaft, and the inner depth of the inner lining is less than the depth of the diaphragm wall of the well shaft. The main body is located inside the lining and is fixedly connected to the inner wall of the lining. Anchor body, which is fixedly connected to the upper part of the main body; Strip-wall type diaphragm walls are installed along the longitudinal direction of the bridge and are spaced apart along the transverse direction of the bridge. These strip-wall type diaphragm walls are located inside the lining and fixed to the lower part of the main body. The bottom of the strip-wall type diaphragm walls extends into the load-bearing layer. The bottom depth of the strip-wall type diaphragm walls is greater than the bottom depth of the shaft-type diaphragm walls, and the top depth of the strip-wall type diaphragm walls is less than the bottom depth of the shaft-type diaphragm walls. The main body includes a top plate and a bottom plate. The top plate is fixed above the bottom plate, and the anchor body is fixedly connected to the top plate. The base slab consists of a first base slab and a second base slab. The first base slab is poured before the second base slab. The first base slab is not initially connected to the strip-wall diaphragm. After the first base slab is poured, it settles under its own weight and comes into full contact with the bottom soil, generating a reaction force from the foundation soil. The top of the first and second base slabs is connected to a top slab. The second base slab is a trumpet-shaped section, with the upper part of the trumpet-shaped section being larger than the lower part. The lower part of the trumpet-shaped section is connected to the upper part of the strip-wall diaphragm. The reaction force of the foundation soil and the strip-wall diaphragm jointly bear the upper load.

2. The composite anchor foundation for a strip-wall type underground continuous wall as described in claim 1, characterized in that, The lower part of the top plate has a tongue and groove tenon, which is set on the side of the lower part of the first part of the top plate above the first part of the bottom plate. The lower part of the first part of the top plate is cast before the second part of the bottom plate.

3. The composite anchor foundation for a strip-wall type underground continuous wall as described in claim 1, characterized in that, The clear distance between the edge of the strip-wall diaphragm and the inner edge of the lining shall not be less than 1m.

4. A strip-wall type diaphragm wall composite anchor foundation according to any one of claims 1-3, characterized in that, The shaft-type diaphragm wall includes a vertical joint, which is a milled joint. The depth of the bottom of the shaft-type diaphragm wall is lower than the depth of the bearing layer. And / or, the lining is arranged in a stepped manner along the depth, with the lower part of the lining being larger than the upper part; And / or, the strip-type diaphragm walls are arranged in parallel at equal intervals.

5. A strip-wall type diaphragm wall composite anchor foundation according to claim 4, characterized in that, The wall spacing of strip-type diaphragm walls is 6d to 10d, where d is the wall thickness of the strip-type diaphragm wall.

6. A strip-wall type diaphragm wall composite anchorage foundation according to claim 5, characterized in that, The strip-wall type diaphragm wall has a vertical joint, and the vertical joint of the strip-wall type diaphragm wall is a rigid joint.

7. A construction method for a strip-wall type diaphragm wall composite anchor foundation, characterized in that, Used for constructing the composite anchor foundation of the strip-wall type underground continuous wall as described in any one of claims 1-6. Includes the following steps: S1: Construction of shaft-type ground connection wall; S2: Construction strip-type diaphragm wall; S3: Excavation of the foundation pit inside the shaft-type diaphragm wall and construction of the inner lining, so that the inner lining and the inner wall of the shaft-type diaphragm wall form an integral structure; S4: Construct the main body layer by layer from the top of the strip-wall diaphragm and the inside of the lining, so that the main body, the lining, and the strip-wall diaphragm form an integral whole. Step S4 includes the following steps: S4.1 After excavating to the top of the strip-wall diaphragm wall to form the bottom of the pit, remove the plain concrete in the top area of ​​the strip-wall diaphragm wall and install trumpet-shaped steel bars at the top of the strip-wall diaphragm wall. S4.

2. Pour the foundation layer and bottom sealing concrete, and then pour the bottom plate part other than the trumpet-shaped steel bars to form the first part of the bottom plate, so that the first part of the bottom plate and the inner lining form an integral whole; S4.

3. Pour the top slab above the first part of the bottom slab to 4m-6m below the top surface of the top slab to form the lower part of the first part of the top slab, and make the lower part of the first part of the top slab and the inner lining form an integral whole; S4.

4. The trumpet-shaped steel bars at the top of the cast-in-place strip-wall diaphragm wall correspond to the bottom slab portion to form a second part of the bottom slab, thus forming a complete bottom slab. S4.

5. Pour the top slab above the second part of the bottom slab to 4m-6m below the top surface of the top slab to form the lower part of the second part of the top slab, thus forming the lower part of the top slab; S4.6: Pour the remaining top slab portion to form the upper part of the top slab, thus forming a complete top slab, and making the strip-walled diaphragm wall, bottom slab, top slab, and inner lining a whole; S5: Construct the anchor body at the top of the main structure, and the construction is completed.

8. The construction method of a strip-wall type underground continuous wall composite anchor foundation according to claim 7, characterized in that, The steps preceding step S1 include: site leveling, followed by construction of guide walls for shaft-type diaphragm walls and strip-type diaphragm walls; In step S1, the first-phase trench section and the second-phase trench section of the diaphragm wall are constructed to form a closed circular ring-shaped diaphragm wall enclosure structure. In step S2, the first-phase trench section and the second-phase trench section of the strip-wall diaphragm wall are constructed to form a parallel strip-wall diaphragm wall structure. In step S3, the soil inside the foundation pit of the well-type diaphragm wall is excavated in layers, and the inner lining is constructed using the reverse construction method, so that the inner lining and the well-type diaphragm wall form an integral whole. In step S5, the anchor blocks and cable saddle supports are poured in layers and sections.

9. A construction method for a strip-wall type underground continuous wall composite anchor foundation according to claim 8, characterized in that, In step S4.4, the lower part of the first part of the top plate is provided with a tongue and groove tenon on the side facing the strip wall.

10. A construction method for a strip-wall type diaphragm wall composite anchor foundation according to claim 8, characterized in that, When constructing the roof slab, construction is carried out layer by layer from bottom to top, with cooling pipes arranged in each layer of the roof slab and anchor steel bars pre-embedded.

11. A construction method for a strip-wall type diaphragm wall composite anchor foundation according to any one of claims 7-10, characterized in that, In step S2, the strip-wall type diaphragm wall in the middle part is constructed first, and then the strip-wall type diaphragm walls on both sides are constructed. And / or, in step S1, before excavating the guide walls on both sides of the shaft-type diaphragm wall and the strip-wall type diaphragm wall, the trench walls on both sides of the shaft-type diaphragm wall and the strip-wall type diaphragm wall are reinforced.

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