OPEN CAISSON STRUCTURES AND CONSTRUCTION METHODS AND THEIR APPLICATION
Patent Information
- Authority / Receiving Office
- ID · ID
- Patent Type
- Patents
- Current Assignee / Owner
- CCCC FIRST HARBOR ENGINEERING CO LTD
- Filing Date
- 2022-05-23
- Publication Date
- 2026-07-13
AI Technical Summary
Open caissons in areas prone to significant subsidence, such as the North China Plain and Jakarta, experience downward drag forces and tilting due to soil settlement, leading to structural damage and height discrepancies that affect normal use.
The open caisson structure incorporates a blade footing part, standard sections with insulating layers comprising a waterproof, elastic buffer, and filler layers, along with guide walls and a flexible catwalk, to isolate the structure from soil subsidence and maintain structural integrity.
The solution effectively isolates the caisson from soil stresses, prevents water ingress, and allows for flexible adjustment to ground subsidence without affecting basement access, thereby reducing structural damage and maintaining functional integrity.
Smart Images
Figure 0_ABST
Abstract
Description
Description OPEN CAISON STRUCTURES AND METHODS OF ITS CONSTRUCTION AND IMPLEMENTATION This application claims priority benefit from Chinese application No. 202210382602.2, filed on April 13, 2022, entitled Open Caisson Structure and Its Application in Deformable Soil and Chinese application No. 202220842144.1, filed on April 13, 2022, entitled Open Caisson Structure Suitable for Deformable Soil, the entire contents of which are incorporated by reference. Invention Techniques This application falls within the field of civil engineering, and relates to an open caisson structure and a method of construction and application thereof. Background of the Invention An open caisson is a structure similar to a wellbore, which is formed by excavating the soil in the well, sinking it to a designed height after overcoming the friction of the well wall by relying on its own gravity, and then covering the bottom with concrete and filling the wellbore, making the foundation of a usable structure or basement, and so on. After an open caisson is previously constructed, there is generally no settlement deformation in the surrounding soil, or no relative displacement between the soil and the open caisson, which will not affect the stress and elevation of the open caisson during use. However, in areas that tend to experience marked subsidence, such as the North China Plain and Jakarta in Indonesia, soil subsidence is large every year, causing downward drag forces and increased pressure on open caissons, with possible tilting or damage to the open caissons. At the same time, the subsidence of the strata produces a height difference between the open caisson and the surrounding ground, which affects the normal use of the basement. Brief Description of the Invention The purpose of this application is to provide an open caisson structure and a method of construction and application thereof, suitable for construction conditions with land subsidence. Based on the first aspect of this application, an open caisson structure is provided, which includes: blade step section; a standard member, which is placed on the blade footing member; and an insulating layer, which is formed between the standard member and the surrounding ground; the insulating layer includes a buffer layer and a filling layer, wherein, the buffer layer is placed between the standard member and the filling layer and is an elastic layer provided on the outer wall of the standard member, and the filling layer is filled with filling material. Optionally, the support layer includes several layers of asphalt sheets, for example, formed by gluing 2 to 4 layers of asphalt sheets. Optionally, the backing layer is 4 mm to 10 mm thick, preferably 5 mm to 8 mm, and is attached to the outer wall of the standard section with asphalt. Asphalt is also used to bond between layers of asphalt sheeting. Optionally, the filling layer has a thickness of 15 cm to 25 cm, preferably 18 cm to 22 cm. Optionally, the filler is coarse spherical particles, with uniform size and virtually free of impurities. Optionally, the filler has a diameter of 20 mm to 40 mm, a density of 2 g / cm3 to 3 g / cm3; and a crushing index of less than or equal to 16%. Next, a waterproofing layer, a buffer layer, and a filling layer are sequentially provided between the outer walls of the standard section and the surrounding soil. Optionally, a waterproofing layer is formed by applying asphalt or cement paste to the outer walls of the standard section. Optionally, a guide wall is provided at the surrounding ground level adjacent to the insulation layer. Optionally, the guide wall has a height of 0.3 m to 0.8 m below and 0.1 m to 0.3 m above the surrounding ground level. Optionally, the blade footing part is placed on the bearing layer, and part or all of the standard part is placed on the soft ground layer, where the bearing layer is placed under the soft ground layer. Optionally, the newly completed open caisson structure is lower than the surrounding ground level. Preferably, a boardwalk is provided between the open caisson structure and the surrounding ground surface. Based on the second aspect of this application, a method of construction of an open caisson structure is provided, which can be adopted for the construction of an open caisson structure described in any of the above technical solutions, and includes the following steps: Construction of the blade footing section: construct the blade footing section after site leveling, and complete the blade footing section by digging evenly under the blade footing section; guide wall construction: constructing guide walls on the ground surface surrounding and adjacent to the blade footing section; sub-standard section construction: construct the first sub-standard section on the blade footing section; formation of insulation layer: constructing a support layer on the outer wall of the first sub-standard section, the support layer is a layer with elasticity; completing the blade footing section and the first sub-standard section by digging uniformly, and filling the filling layer formed between the support layer and the surrounding soil with filling material; standard section formation: repeating the above steps of sub-standard section construction and isolation layer formation, to construct a number of sub-standard sections overlapping on the first sub-standard section until the open caisson structure closes at the designed height; and open caisson structure formation: casting concrete at the bottom of the blade footing section, and forming the bottom of the open caisson structure together with the blade footing section; thus completing the main part of the open caisson structure. Optionally, in the step of forming the isolation layer, 2 to 4 layers of asphalt sheets are attached to the outer wall of each sub-standard section to form a buffer layer. The layers of asphalt sheets are felt attached to each other. More specifically, the outer wall of each sub-standard section is coated with asphalt, and 2 to 4 layers of asphalt sheets are attached to the outer wall of each sub-standard section to form a buffer layer; and the layers of asphalt sheets are also attached with asphalt. Optionally, in the insulation layer formation step, the outer wall of each sub-standard section is coated with a waterproof layer, and a waterproof layer is formed between the sub-standard section and the supporting layer. Optionally, a waterproof layer is formed by coating asphalt or cement paste on the outer wall of each sub-standard section. Optionally, in the standard section forming step, the open caisson structure is lower than the surrounding ground level to allow for subsequent lowering of the surrounding ground. Optionally, after the standard section is formed, the blade footing section is placed on the support layer, and part or all of the standard section is placed on the soft soil layer, where the support layer is placed under the soft soil layer. Optionally, once the open caisson structure is established, walkways are provided between the open caisson structure and the surrounding ground. In addition, it is understood that the technical solutions and related parameters in the above open caisson structure can also be applied to the current construction method, which includes but is not limited to the thickness of the support layer, the thickness of the filling layer, the filling parameters, and the parameters of the guide wall, which will not be repeated here. Based on the third embodiment of this application, the application of an open hole structure on deformable soil is provided, and the open hole structure is the open hole structure described in one of the technical solutions above. Compared to the previous invention, the beneficial effects of this application are as follows. In the open caisson structure provided in at least one embodiment of the present application, the open caisson wall is isolated from the surrounding soil by an insulating layer, thereby eliminating the detrimental effects of additional stresses caused by subsidence of the surrounding soil. In the open caisson structure provided in at least one embodiment of the present application, the insulation layer can prevent water leakage to ensure dry and normal use of the basement in the open caisson structure. In the open caisson structure provided in at least one embodiment of the present application, a boardwalk, which can be flexibly adjusted to the subsidence of the ground surface, is provided between the open caisson structure and the surrounding ground, without affecting normal access to the basement in the open caisson structure in the event of subsidence of the ground layer. Brief Description of the Picture Picture 1 is a construction diagram of the blade footing based on one embodiment; Figure 2 is a construction diagram of a standard part based on one embodiment; Figure 3 is a construction diagram of a standard part based on one embodiment; Figure 4 is a schematic diagram of an open caisson structure based on Figure one embodiment; 5 is an enlarged view of Part A in Figure 4; Figure 6 is an enlarged view of Part B in Figure 4; Figure 7 is a schematic diagram of an open caisson structure newly constructed; Figure 8 is a schematic diagram of the first change of the open caisson structure; Figure 9 is a schematic diagram of the changes to the two open caisson structures; where: 1 Blade step section; 2 The bottom of the caisson structure is open; 3 Standard parts; 31 Exterior walls of standard sections; 301 First sub-standard section; 4 Surrounding land; 41 Surrounding ground surface; 5 Layers of insulation; 51 Waterproof coating; 52 Buffer layers; 53 Fill layer; 6 Guide walls; 71 Bearing layers; 72 Soft soil layer; and, 8 Footbridges. Complete Description of the Invention The technical solutions of this application will be described in detail below in combination with specific embodiments. However, it should be understood that elements, structures and features in one embodiment may also be advantageously combined into other embodiments without further explanation. In explaining this application, it should be noted that terms such as first and second are used for descriptive purposes only, and are not to be understood as indicating or implying relative importance, or implicitly indicating the number of technical features shown. Therefore, the features defined by first and second may explicitly or implicitly include one or more of these features. In explaining this application it should be noted that the terms up, down, down, in and the like indicate positional relationships or positions based on the positional relationships based on Figure 4, solely for the convenience of illustrating this application and a simplified description, but do not indicate or imply that the devices or elements in question must be of a particular orientation, constructed and operated in a particular orientation and therefore should not be construed as limiting this application. In the explanation of this application, it should be noted that the terms connecting, connecting and connected should be understood in a broad sense unless specified and limited otherwise clearly. For example, they can be fixed connections, removable connections, or integrated connections; it may be a direct connection or an indirect connection through an intermediate media, and it may be an internal connection of two elements. For those skilled in the art, the specific meaning of the terms mentioned above in this application can be understood in specific circumstances. As shown in Figures 1 to 6, an open caisson structure is provided in the first embodiment of this application, which includes: a blade footing member (1), the lower part of which can be constructed into the lower part (2) of an open caisson structure after sealing the base by concreting; and, a standard member (3), which is provided on the blade footing member (1) to form the main body of the open caisson structure together with the blade footing member (1). The standard member (3) can include a plurality of sub-standard members, namely, a first sub-standard member (301), a second sub-standard member (302),.., and the Nth sub-standard member from bottom to top. An insulating layer (5) is formed between the outer wall (31) of the standard part (3) and the surrounding soil (4), which includes a waterproof layer (51), a buffer layer (52) and a filling layer (53) respectively; wherein, the waterproof layer (51) is provided on the outer wall (31) of the standard part (3), and the filling layer (53) is placed between the buffer layers (52) and the surrounding soil (4). The insulating layer (5) plays a role of isolation and buffer between the standard part (3) and the surrounding soil (4). As an embodiment, a waterproof layer (51) is constructed by coating asphalt or cement paste on the outer wall (31) of the standard member (3), primarily to prevent water from entering the open caisson structure. As an embodiment, the backing layer (52) is an elastic layer attached to the outer wall (31) of the standard part (3). For example, the backing layer (52) may be attached to the outer wall (31) of the standard part with asphalt paste or cement that serves as a waterproof layer (51), and adjacent to the waterproof layer (51). The backing layer (52) has elasticity and flexibility, and may be formed by asphalt sheets. For example, the backing layer may be composed of 2 to 4 layers of asphalt sheets, such as the attachment of three layers of asphalt sheets. Between each layer of asphalt sheets, asphalt may also be used as an adhesive to bond them. If appropriate, the backing layer (52) may also be other elastic layers, such as rubber layers, which may not be as durable and flexible as asphalt sheets.The support layer (52) has a thickness of 4 mm to 10 mm, preferably 5 mm to 8 mm, such as 6 mm, 7 mm, 8 mm, and 9 mm and so on. The buffer layer (52) is located between the outer wall (31) of the standard member (or outside the waterproof layer (51)) and the filling layer (53), acting as a cushion. When the filling layer (53) moves along with the surrounding soil (4), the buffer layer (52) can move a short distance or deform to buffer the displacement and absorb the friction generated by the displacement, thereby reducing the damage to the waterproof layer (51) and the outer wall (31) of the standard member. Asphalt felt is adopted for two reasons; the first is that asphalt felt can deform well and is not easy to break; and the second is that asphalt felt has better corrosion resistance and durability, and is suitable for long-term use in underground works. In addition, asphalt and other adhesive materials between the layers of the asphalt felt sheet and between the buffer layer (52) and the outer wall (31) can prevent further water.To some extent, when the waterproof layer (51) is made of asphalt which can also be used as an adhesive for the backing layer (52), there is some overlap between the waterproof layer (51) and the backing layer (52). As an embodiment, the filling layer (53) has a thickness of 15 cm to 25 cm, such as 18 cm, 20 cm, and 22 cm and so on, and is filled with a non-fragile filling material with uniform size, clean surface, little dirt and strong hardness. The filling material can be qualified sand gravel, cobblestone, clean river sand, and so on, and may also be small hard and round balls. As a particular embodiment, the filling material has a diameter of 20 mm to 40 mm, such as 22 mm, 25 mm, 28 mm, 30 mm, 32 mm, 35 mm, 38 mm and so on; the filling material has a density of 2 g / cm3 to 3 g / cm3, such as 2.2 g / cm3, 2.4 g / cm3' 2.6 g / cm3' 2.8 g / cm3 and so on; and the filler has a crushing index of less than or equal to 16%, such as 15%, 14%, 13%, 12%, 11%, 10%, 8%, and so on. The filling material in the filling layer (53) can allow for better mutual isolation between the open caisson structure and the surrounding soil (4). In addition, the filling material is not susceptible to bonding and can thus provide stable support. As an optional embodiment, an insulating layer (5) is primarily provided over the blade step portion (1). As an optional embodiment, as shown in Figures 3 and 6, a guide wall (6) is provided on the surface (41) of the surrounding soil (4) near the filling layer (53). Specifically, the guide wall (6) has a height of 0.3 m to 0.8 m below the surface (41) of the surrounding soil (4), such as 0.4 m, 0.5 m, 0.6 m, 0.7 m and so on, and has a height of 0.1 m to 0.3 m above the surface (41) of the surrounding soil (4), such as 0.1 m, 0.15 m, 0.2 m, 0.25 m and so on. On the one hand, the guide wall (6) can prevent impurities such as dirt and small particles in the surrounding soil (4) from entering the filling layer (53), and prevent the clumping of the filling material; On the other hand, the guide wall (6) can also prevent the collapse of the surrounding soil surface. As shown in Figure 4, the blade footing part (1) is placed on the bearing layer (71), and part or all of the standard part (3) is placed on the soft soil layer (72). The bearing layer (71) is placed under the soft soil layer (72). The soft soil layer (72) mainly refers to the soil layer that is prone to deformation. The blade footing part (1) placed on the bearing layer (71) can well support the open caisson structure and prevent it from moving or deforming along with the deformation of the soft soil layer (72) in the surrounding soil. As shown in Figure 7, the newly constructed open caisson structure is lower than the surface (41) of the surrounding ground. A connecting board (8) may be provided between the open caisson structure and the surface (41) of the surrounding ground to form a slope for normal vehicle travel, etc. The board (8) may be made of steel plates or concrete plates with both ends arranged on the open caisson structure and on the surrounding ground. As shown in Figure 7, a new open caisson structure is constructed. To allow for subsequent settlement of the surrounding soil, the open caisson structure is constructed lower than the surrounding soil surface (41), and the footboards (8) are inclined upward. After a period of use, as shown in Figure 8, the open caisson structure subsides less or does not subside because the bottom (2) is placed on a hard bearing layer (71), the surrounding soil (4) subsides more, the open caisson structure is approximately as high as the surrounding soil surface (41), and the footboards (8) gradually become horizontal. After a long period of use, as shown in Figure 9, the surrounding soil (4) subsides even more, the open caisson structure is higher than the surrounding soil surface (41), and the footboards (8) are inclined downward. In a second embodiment of the present application, a method of constructing an open pit structure suitable for deformable soil is provided, which can be adopted for the construction of an open pit structure described in any of the preceding solutions; and the construction method includes the following steps. S1: yellow sand is paved along the position approximately corresponding to the open caisson wall after site leveling, and the stock timber is laid on the yellow sand; and the blade footing part (1) laid on the stock timber is constructed with a plurality of blade footing blocks, as shown in Figure 1. S2: under the blade footing section (1), yellow sand is dug out while the stored wood is pulled out symmetrically. S3: uniform excavation under the blade footing section (1) constructing the blade footing section (1) of the open caisson structure settled below the ground surface (i.e., the surface (41) of the surrounding ground). S4: the guide wall (6) is constructed on the surface (41) of the surrounding ground adjacent to the blade footing section (1). The guide wall (6) is provided vertically, with a height of about 0.5 m below and 0.1 m to 0.2 m above the surface (41) of the surrounding ground. S5: the first sub-standard section (301) is constructed on top of the blade footing section (1). Asphalt is painted on the outer wall of the first sub-standard section (301) to form a waterproof layer (51), then three layers of asphalt sheets with a total thickness of 5 mm to 8 mm are attached to it, forming a support layer (52). S6: the open caisson structure descends through uniform excavation, and the fill layer (53) formed between the support layer (52) and the surrounding soil (4) is filled with a fill material, such as sand gravel, cobblestones, or round balls. S7: S5 and S6 are repeated to construct more sub-standard sections (302) on the first sub-standard section (301), until the open caisson structure reaches the designed elevation. S8: the inside of the open caisson structure is cleaned, and perform base sealing by concrete molding together with the blade footing part (1) to form the bottom (2) of the open caisson structure. S9: other structures (such as garages) are constructed in an open caisson structure and then the open caisson structure is closed at the top. It is understood that the above steps are not strictly sequential but may be adjusted based on actual construction conditions. Therefore, the sequence described here will not be an absolute limitation on this application. In a third embodiment of the present application, an application of an open caisson structure to deformable soil is provided, wherein the open caisson structure is the open caisson structure described in one embodiment above. The lower part (2) of the open caisson structure is placed on a bearing layer (71), and part or all of the standard part (3) is placed on a soft soil layer (72). It can be understood that the technical features and technical parameters of the open caisson structure in the first embodiment can also be applied simultaneously to the second embodiment and the third embodiment, so that there is no redundant description in this embodiment. The embodiments are described only as preferred embodiments of this application, and are not intended to limit the scope of this application. Any modifications and improvements made to the technical solution of this application by a person of ordinary skill in the art without departing from the spirit of the design of this application will fall within the scope of protection confirmed by the claims of this application.
Claims
1. An open caisson structure, including: a blade step member, a standard member, disposed on the blade step member; and an insulating layer, formed between the standard portion and the surrounding soil; the insulating layer includes a buffer layer and a filler layer; wherein, the backing layer is placed between the standard member and the filler layer and is an elastic layer provided on the outer wall of the standard member, and the filler layer is filled with the filler material.
2. The open caisson structure according to claim 1, wherein, the support layer includes multiple layers of asphalt sheets.
3. The open caisson structure according to claim 2, wherein, the support layer has a thickness of 4 mm to 10 mm, and is attached to the outer wall of the standard member with asphalt; and asphalt is also used for attaching between the layers of the asphalt sheet.
4. An open caisson structure according to any one of claims 1-3, wherein the filling layer has a thickness of 15 cm to 25 cm; and the filling material has a diameter of 20 mm to 40 mm, a density of 2 g / cm3 to 3 g / cm3, and a crushing index of less than or equal to 16%.
5. An open caisson structure according to any of claims 1-3, wherein, a waterproof layer, a support layer and a fill layer are provided sequentially between the outer wall of the standard section and the surrounding soil; and the waterproof layer is formed by coating asphalt or cement paste on the outer wall of the standard section.
6. An open caisson structure according to any of claims 1-3, wherein, guide walls are provided at the surrounding ground surface adjacent to the insulating layer.
7. An open caisson structure according to any one of claims 1-3, wherein, the blade footing portion is placed on the bearing layer, and part or all of the standard portion is placed on the soft soil layer, wherein the bearing layer is placed below the soft soil layer; the newly completed open caisson structure is lower than the surrounding ground surface; and a footing is provided between the open caisson structure and the surrounding ground surface.
8. A method of constructing an open caisson structure according to any one of claims 1-7, wherein, comprising the following steps: construction of a blade footing section: constructing a blade footing section after leveling the site, and completing the blade footing section by uniformly excavating under the blade footing section; construction of a guide wall: constructing a guide wall on the ground surface surrounding and adjacent to the blade footing section; construction of a sub-standard section: constructing a first sub-standard section on the blade footing section; formation of an isolation layer: constructing a support layer on the outer wall of the first sub-standard section, the support layer being a layer with elasticity; completing the blade footing section and the first sub-standard section by uniformly excavating, and filling the filler layer formed between the support layer and the surrounding soil with filler material;standard section formation: repeating the sub-standard section construction steps and insulation layer formation steps, to construct a number of overlapping sub-standard sections until the open caisson structure lowers to the designed height; and forming an open caisson structure: casting concrete on the bottom of the blade footing portion, and forming the bottom of the open caisson structure together with the blade footing portion; thus completing the body of the open caisson structure.; 9. The construction method of an open caisson structure according to claim 8, wherein, in the step of forming an insulating layer, 2 to 4 layers of asphalt sheets are affixed to the outer wall of each sub-standard section to form a support layer; and the layers of asphalt sheets are affixed to each other.
10. The method of constructing an open caisson structure according to claim 8 or 9, wherein, in the step of forming the insulation layer, a waterproof layer is formed by coating asphalt or cement paste on the outer wall of each sub-standard section; and a buffer layer is placed between the waterproof layers and the filling layer.
11. Open caisson structure construction method according to claim 8 or 9, where in the construction step of the guide wall, the guide wall has a height of 0.3 m to 0.8 m below and 0.1 m to 0.3 m above the surrounding ground surface.
12. Application of an open caisson structure to deformable soil, and the open caisson structure is an open caisson structure based on any one of claims 1-7.