Open caisson sinking assisting system with directivity

Abstract

The utility model provides an open caisson sinking assisting system with directivity, which belongs to the technical field of open caisson construction, and comprises an open caisson body, a plurality of steel bar stress meters, a plurality of steel pipes, a stress monitoring system and a water injection system, the plurality of steel bar stress meters are arranged in the open caisson body and are uniformly distributed along the circumferential direction of the open caisson body; a cable connected with the reinforcement stress meter is led out from the upper end of the well wall; the multiple steel pipes are connected to the well wall of the open caisson body, two water outlets are evenly distributed in each steel pipe in the axial direction of the steel pipe, and the water outlet direction of the water outlets is tangent to the well wall. The stress monitoring system is electrically connected with the plurality of reinforcement stress gauges and is used for receiving and recording frequency information of the reinforcement stress gauges; and water is injected into the at least one steel pipe according to frequency change information of the steel bar stress meter so as to weaken the peripheral soil body of the well wall. According to the open caisson sinking assisting system with directivity, the local side friction resistance of the well body can be reduced in the directivity, the uncertainty of open caisson sinking assisting is reduced, operation is easy and convenient, and safety is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of open caisson construction, and more specifically, relates to an open caisson sinking assistance system with directivity. Background Technique

[0002] An open caisson is a well structure made on the ground, which uses manual or mechanical means to remove the soil inside the well and sinks into the soil to a certain depth under its own weight. It has the characteristics of large overall stiffness, high bearing capacity, good stability, strong impermeability and excellent seismic performance, and is widely used in the construction field.

[0003] In the construction of the open caisson method, the sinking force of the open caisson mainly consists of the difference between its own weight, the tip resistance of the cutting edge, the side friction resistance and the buoyancy. Usually, the way of reducing the tip resistance of the cutting edge by excavating the soil under the cutting edge is adopted to make the open caisson passively sink under its own weight. During the sinking process of the open caisson, there are problems such as excessive side resistance of the open caisson wall resulting in slow sinking, non-sinking, and caisson body deviation.

[0004] When the local sinking of the open caisson is difficult or there is deviation, generally, the methods of reducing resistance or adding weight are used to assist sinking and correct deviation. The commonly used resistance reduction measures are slurry jackets, sand filling in the caisson wall, air curtain method, etc., which are mainly for resistance reduction and sinking assistance within the entire range of the caisson body. For local sinking assistance or sinking control, measures such as adding weight still need to be supplemented. However, the sinking assistance effect of this kind of sinking assistance method is not ideal, and it cannot specifically reduce the side friction resistance in the difficult sinking area of the open caisson. Content of the Utility Model

[0005] The purpose of the utility model is to provide an open caisson sinking assistance system with directivity, aiming to solve the technical problem that the sinking assistance effect of the existing open caisson sinking assistance method is not ideal and it cannot specifically reduce the side friction resistance in the difficult sinking area of the open caisson.

[0006] To achieve the above purpose, the technical solution adopted by the utility model is: to provide an open caisson sinking assistance system with directivity, including:

[0007] An open caisson body, the open caisson body includes a well wall and a cutting edge;

[0008] A plurality of reinforcing bar strain gauges, all arranged inside the open caisson body, evenly distributed along the circumference of the open caisson body, and the cables connected to the reinforcing bar strain gauges are led out from the upper end of the well wall;

[0009] A plurality of steel pipes, all connected to the well wall of the open caisson body, evenly distributed along the outer circumference of the open caisson body, the steel pipes are arranged vertically, the upper ends of the steel pipes extend out of the upper end of the well wall, and two water outlets are evenly distributed along the axial direction of each steel pipe, and the water outlet directions of the water outlets are arranged tangent to the well wall;

[0010] A stress monitoring system, electrically connected to a plurality of the steel bar stress gauges respectively, for receiving and recording the frequency information of the steel bar stress gauges;

[0011] A water injection system, having a water injection end for connecting to the upper end of at least one of the steel pipes, and the water injection system is used for injecting water into the steel pipes;

[0012] Wherein, water is injected into at least one of the steel pipes according to the frequency change information of the steel bar stress gauges to weaken the soil outside the wellbore.

[0013] In a possible implementation manner, the stress monitoring system includes a frequency meter.

[0014] In a possible implementation manner, a plurality of steel supports are fixedly connected to the wellbore along its circumferential direction, and a plurality of the steel supports are arranged along the height direction of the caisson body, and the outer wall of the steel support is used for contacting the soil.

[0015] In a possible implementation manner, the steel support includes an inner support and an outer support both connected to the wellbore, and the inner support is arranged inside the outer support.

[0016] In a possible implementation manner, along the height direction of the caisson body, a plurality of the steel bar stress gauges are arranged in two rows.

[0017] In a possible implementation manner, the distance between the bottom end of the steel pipe and the top of the cutting edge is 0.4 - 0.6 meters.

[0018] In a possible implementation manner, the distance between two water outlets on each steel pipe is 0.9 - 1.1 meters.

[0019] In a possible implementation manner, the diameter of the water outlet is 4 - 6 mm.

[0020] In a possible implementation manner, the distance between the vertical steel bar stress gauge of the caisson body and the upper end of the cutting edge of the caisson body is 0.8 - 1.2 meters.

[0021] In a possible implementation manner, a plastic hose is arranged around the outer wall of the cable connected to the steel bar stress gauge, and the plastic hose is used for protecting the cable.

[0022] The beneficial effects of a directional caisson sinking assistance system provided by the present utility model are as follows: Compared with the prior art, a directional caisson sinking assistance system of the present utility model includes a caisson body, a plurality of reinforcing bar stress gauges, a plurality of steel pipes, a stress monitoring system, and a water injection system. The caisson body includes a well wall and a cutting edge; a plurality of reinforcing bar stress gauges are all arranged inside the caisson body and are evenly distributed along the circumferential direction of the caisson body. The cables connected to the reinforcing bar stress gauges are led out from the upper end of the well wall; a plurality of steel pipes are all connected to the well wall of the caisson body and are evenly distributed along the outer circumferential direction of the caisson body. The steel pipes are arranged vertically. The upper ends of the steel pipes extend out of the upper end of the well wall. Two water outlets are evenly distributed along the axial direction of each steel pipe, and the water outlet directions of the water outlets are tangent to the well wall; the stress monitoring system is electrically connected to a plurality of reinforcing bar stress gauges respectively and is used for receiving and recording the frequency information of the reinforcing bar stress gauges; the water injection system has a water injection end for connecting at least one upper end of the steel pipe, and the water injection system is used for injecting water into the steel pipes; wherein, water is injected into at least one steel pipe according to the frequency change information of the reinforcing bar stress gauges to weaken the soil outside the well wall, solving the technical problems that the sinking assistance effect of the caisson sinking assistance method used in the prior art is not ideal and the side friction resistance in the difficult area of caisson sinking cannot be reduced targeted. It can directionally reduce the side friction resistance of the local part of the well body, reduce the uncertainty of caisson sinking assistance, is easy to operate, and has high safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a top view structural schematic diagram of a directional caisson sinking assistance system provided by an embodiment of the present utility model;

[0025] Figure 2 is Figure 1 the sectional view along the line A-A in

[0026] Figure 3 is Figure 1 the enlarged view of the structure at B in

[0027] Description of the reference numerals:

[0028] 1. Caisson body; 11. Well wall; 12. Cutting edge;

[0029] 2. Reinforcing bar stress gauge; 21. Cable;

[0030] 3. Steel pipe; 31. Water outlet;

[0031] 4. Stress monitoring system;

[0032] 5. Water injection system;

[0033] 6. Steel support; 61. Inner support; 62. Outer support. Detailed implementation manners

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0035] Please refer to Figures 1 to 3 together. Now, a directional caisson sinking assistance system provided by the present utility model will be described. The directional caisson sinking assistance system includes a caisson body 1, a plurality of steel bar stress gauges 2, a plurality of steel pipes 3, a stress monitoring system 4 and a water injection system 5. The caisson body 1 includes a well wall 11 and a cutting edge 12; a plurality of steel bar stress gauges 2 are all arranged inside the caisson body 1 and are evenly distributed along the circumference of the caisson body 1. The cable 21 connected to the steel bar stress gauge 2 is led out from the upper end of the well wall 11; a plurality of steel pipes 3 are all connected to the well wall 11 of the caisson body 1 and are evenly distributed along the outer circumference of the caisson body 1. The steel pipes 3 are arranged vertically. The upper ends of the steel pipes 3 extend out of the upper end of the well wall 11. Two water outlets 31 are evenly distributed along the axial direction of each steel pipe 3, and the water outlet direction of the water outlet 31 is tangent to the well wall 11; the stress monitoring system 4 is electrically connected to a plurality of steel bar stress gauges 2 respectively for receiving and recording the frequency information of the steel bar stress gauges 2; the water injection system 5 has a water injection end for connecting the upper ends of at least one steel pipe 3, and the water injection system 5 is used for injecting water into the steel pipes 3; wherein, water is injected into at least one steel pipe 3 according to the frequency change information of the steel bar stress gauge 2 to weaken the soil outside the well wall 11.

[0036] Compared with the prior art, the directional caisson sinking assistance system provided by the present utility model adopts a method that can reduce the local resistance of the well body and obtain the stress state of the caisson, specifically reduces the side friction resistance in the difficult area of the caisson sinking, monitors the stress state of the well body, masters the information of the caisson sinking state, realizes directional resistance reduction, reduces auxiliary measures, and improves the construction efficiency, which has practical significance. By using the stress monitoring system 4 to monitor the change of the steel bar stress of the caisson body 1 and injecting water into the steel pipes 3, the side friction resistance received by the caisson can be reduced in sections, the stability of other sections of the well body is maintained, the potential safety risk of the well body sinking is reduced, and the technical problems that the sinking assistance effect of the caisson sinking assistance method used in the prior art is not ideal and the side friction resistance in the difficult area of the caisson sinking cannot be specifically reduced are solved. It can directionally reduce the side friction resistance of the local well body, reduce the uncertainty of the caisson sinking assistance, is easy to operate and has high safety.

[0037] The water outlet direction of the water outlet 31 is tangent to the well wall 11. The jet water flow will radially cut and weaken the soil body adjacent to the well wall 11, reduce the lateral friction resistance received by the open caisson, maintain the stability of other sections of the well body, and reduce the potential safety risks of the well body sinking.

[0038] The reinforcing bar stress gauge 2 can monitor the stress of the well body (open caisson body 1) and the change of the lateral friction resistance of each section in segments, reflect the reduction state of the lateral friction resistance of the soil body by the jet water flow, effectively guide the auxiliary sinking operation, and at the same time, through stress monitoring, the tensile fracture failure of the well body under the action of the lateral friction resistance can be prevented.

[0039] In some embodiments, please refer to Figures 1 to 3 , the stress monitoring system 4 includes a frequency meter. Through the frequency meter, the frequency change state of the reinforcing bar stress gauge 2 can be monitored in real time. The staff can determine whether to perform operations such as water injection according to the frequency change state. This frequency meter is a product of the prior art, and its operation principle and function will not be described here.

[0040] To enhance the stiffness of the well wall 11 and facilitate the construction of the open caisson, in some embodiments, please refer to Figures 1 to 3 , a plurality of steel supports 6 are fixedly connected to the well wall 11 along its circumferential direction. A plurality of the steel supports 6 are arranged along the height direction of the open caisson body 1, and the outer wall of the steel support 6 is used to contact the soil body. The steel support 6 is triangular and is arranged in a vertical strip shape, which is easy to perform the open caisson operation during the open caisson construction. The steel support 6 is made of steel and is fixedly connected to the well wall 11.

[0041] Preferably, the steel pipe 3 can be arranged inside the steel support 6. The steel support 6 plays a role in fixing and protecting the steel pipe 3, but the steel support 6 is arranged to avoid the water outlet 31, that is, the steel support 6 does not affect the jet water flow of the water outlet 31. The steel support 6 is similar to a kind of fixing part or locking part, such as a hoop, a fastener, etc., which can fix the steel pipe 3 and prevent it from being deflected, displaced, etc., so as to affect the direction of the jet water flow. A plurality of the steel supports 6 are arranged at equal intervals along the height direction of the open caisson body 1. The lower port of the steel pipe 3 is closed, and the upper port is used to communicate with the water injection end of the water injection system 5. The water outlet 31 is arranged between two adjacent steel supports 6, and the jet water flow jets out from between the two steel supports 6.

[0042] In some embodiments, please refer to Figures 1 to 3 , the steel support 6 includes an inner support 61 and an outer support 62 both connected to the well wall 11, and the inner support 61 is arranged inside the outer support 62. The inner support 61 and the outer support 62 have the same structure and shape but different sizes, can resist deformation, and have higher strength. The inner support 61 is sleeved inside the outer support 62.

[0043] In some embodiments, please refer to Figures 1 to 3, along the height direction of the caisson body 1, a plurality of the steel bar stress gauges 2 are arranged in two rows, that is, the two rows of steel bar stress gauges 2 are located at different heights. The steel bar stress gauge 2 is a product using the existing technology, which can realize the real-time monitoring of the stress of the steel bars in the caisson body 1. The installation method of the steel bar stress gauge 2 and the like can refer to the existing technology and will not be described herein. An installation hole is provided inside the caisson body 1, and the cable 21 passes through the installation hole.

[0044] In some embodiments, please refer to Figures 1 to 3 , the distance between the bottom end of the steel pipe 3 and the top of the cutting edge 12 is 0.4 - 0.6 meters, preferably 0.5 meters.

[0045] In some embodiments, please refer to Figures 1 to 3 , the distance between the two water outlets 31 on each steel pipe 3 is 0.9 - 1.1 meters, preferably 1 meter.

[0046] In some embodiments, please refer to Figures 1 to 3 , the diameter of the water outlet 31 is 4 - 6 mm, preferably 5 mm.

[0047] In some embodiments, please refer to Figures 1 to 3 , the distance between the vertical steel bar stress gauge 2 on the caisson body and the upper end of the cutting edge 12 of the caisson body is 0.8 - 1.2 meters, preferably 1 meter.

[0048] In some embodiments, please refer to Figures 1 to 3 , a plastic hose is arranged around the outer wall of the cable 21 connected to the steel bar stress gauge 2, and the plastic hose is used to protect the cable 21.

[0049] The construction method of the caisson sinking assistance system of the present utility model sequentially includes the following steps:

[0050] Step 1) Vertically arrange steel bar stress gauges 2 at an interval of 1 meter in the first section of the well wall 11 in the upper part of the cutting edge 12 of the caisson body 1, and arrange a plurality of steel bar stress gauges 2 equidistantly in the circumferential direction of the caisson body 1, and wrap the cable 21 with a plastic hose;

[0051] Step 2) Arrange steel pipes 3 equidistantly in twelve equal parts along the circumferential direction of the caisson body 1 at the top of the well wall 11. The steel pipes 3 are 6 - minute steel pipes 3, and each steel pipe 3 is provided with two water outlets 31;

[0052] Step 3) During the caisson construction, when a local sinking of the caisson body 1 is difficult, inject water into the steel pipe 3 in the difficult - sinking section, and at the same time seal the upper ends of other steel pipes 3. The water outlet 31 of the steel pipe 3 sprays water, and the sprayed water flow reduces the side friction resistance received by the well wall 11. When the sinking coefficient is calculated to be greater than 1.0 through the stress monitoring system 4 monitoring and recording the frequency change of the steel bar stress gauge 2, stop the water supply to realize the sinking of the well body in the predetermined section.

[0053] In the utility model, a high-pressure water jet pipe (steel pipe 3) is annularly arranged on the outer side of the caisson wall 11, and a reinforcing bar stress gauge 2 is annularly arranged inside the well wall 11. The local cutting of the soil body by water is used to reduce the side friction resistance, and the reinforcing bar stress gauge 2 is used to analyze the stress state of the well body, and water jetting is carried out on the local well wall 11 section with difficult settlement to reduce the resistance and assist in sinking, so as to realize directional sinking assistance during the sinking process of the caisson.

[0054] Based on the sinking principle of the caisson and the stress analysis of the well body during sinking, by annularly arranging a plurality of single water jet pipes (steel pipe 3), the side friction resistance of the local well body can be directionally reduced. The sinking coefficient of the caisson and the change state of the side friction resistance are obtained through the stress test of the well body, which can provide a judgment basis for stopping water jetting, reduce the uncertainty of caisson sinking assistance, realize the sinking of the caisson by its own weight, without the need to be equipped with ballast materials and equipment, and the monitoring during this period can be automatically calculated, with simple operation and high safety.

[0055] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A directional caisson sinking aid system, characterized in that: include: A caisson body, the caisson body comprising a well wall and a blade foot; A plurality of steel bar stress gauges are arranged inside the caisson body and are evenly distributed along the circumference of the caisson body, and the cables connected to the steel bar stress gauges are led out from the upper end of the well wall; A plurality of steel pipes are connected to the wall of the caisson body and are evenly distributed along the outer circumference of the caisson body. The steel pipes are arranged vertically, and the upper ends of the steel pipes extend out of the upper end of the wall. Each of the steel pipes has two water outlets evenly distributed along its axial direction, and the water outlet direction of the water outlet is arranged tangent to the wall. A stress monitoring system, electrically connected to the plurality of the steel bar stress gauges, for receiving and recording frequency information of the steel bar stress gauges; A water injection system, having a water injection end for connecting to the upper end of at least one of the steel pipes, the water injection system being used to inject water into the steel pipe; Wherein, water is injected into at least one of the steel pipes according to the frequency change information of the steel bar stress gauge to weaken the soil around the well wall.

2. A directional caisson sinking aid system as claimed in claim 1, characterized in that: The stress monitoring system includes a frequency meter.

3. The directional caisson sinking aid system according to claim 1, characterized in that: The well wall is evenly and fixedly connected with a plurality of steel supports along its circumference. A plurality of the steel supports are extended along the height direction of the caisson body. The outer walls of the steel supports are used to contact the soil.

4. The directional caisson sinking aid system according to claim 3, characterized in that: The steel support comprises an inner support and an outer support both connected to the well wall, and the inner support is arranged inside the outer support.

5. The directional caisson sinking aid system according to claim 1, characterized in that: Along the height direction of the caisson body, a plurality of the steel bar stress gauges are arranged to form two rows.

6. The directional caisson sinking aid system according to claim 1, characterized in that: The distance between the bottom end of the steel pipe and the top of the blade foot is 0.4-0.6 meters.

7. The directional caisson sinking aid system according to claim 1, characterized in that: The distance between the two water outlets on each steel pipe is 0.9-1.1 meters.

8. The directional caisson sinking aid system according to claim 1, characterized in that: The water outlet diameter is 4-6 mm.

9. The directional caisson sinking aid system according to claim 1, characterized in that: The vertical distance between the steel bar stress gauge and the upper end of the blade foot of the caisson body is 0.8-1.2 meters.

10. The directional caisson sinking aid system according to claim 1, characterized in that: A plastic hose is arranged around the outer wall of the cable connected to the steel bar stress gauge, and the plastic hose is used to protect the cable.

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