Weak sedimentary stratum underground diaphragm wall reinforcement cage hoisting control method

Abstract

The invention provides a hoisting control method for a reinforcement cage of an underground diaphragm wall in a soft sedimentary stratum, which is suitable for the field of underground diaphragm wall construction and comprises the steps of manufacturing of the reinforcement cage of the underground diaphragm wall, installation of monitoring point positions, selection of hoisting equipment, starting of hoisting, control of the process below and completion of hoisting of the reinforcement cage of the underground diaphragm wall. According to the hoisting control method for the underground diaphragm wall reinforcement cage in the soft sedimentary stratum, the position adjustment of the reinforcement cage can be accurately controlled based on detection data analysis, the safety risk possibly occurring when the reinforcement cage is hoisted in the soft sedimentary stratum is reduced, and the hoisting control method can be widely applied to the field of underground diaphragm wall construction.

Description

Technical Field

[0001] The invention relates to a method for hoisting and controlling a steel cage of an underground continuous wall in a soft sedimentary stratum, and is applicable to the field of underground continuous wall construction. Background Art

[0002] In the soft sedimentary strata of marine-continental interphase, the construction of underground continuous walls faces many technical challenges. Such strata are usually composed of silt, silty soil, fine sand, medium-coarse sand, etc., with a depth of up to tens of meters, and have unstable characteristics such as fluidity, low permeability, and high compressibility. These characteristics lead to the risk of quicksand, collapse, water gushing, collapse, uneven settlement, water disintegration, and rapid reduction in strength during construction.

[0003] During the hoisting construction of the steel cage for underground continuous wall construction in soft sedimentary strata, on the one hand, due to the complexity of the strata and the large length of the steel cage, it is difficult to calibrate the verticality, and it is not properly placed and difficult to enter the slot, and the deviation is often greater than the requirements of the specifications; on the other hand, during the hoisting process, due to the uncertainty of geological conditions, the steel cage often deflects, and the friction with the slot wall causes the slot wall to peel and collapse. The steel cage floats when the concrete is poured, and the quality is difficult to guarantee. At the same time, when facing construction under adverse geological conditions such as soft sedimentary strata in the marine-terrestrial alternating phase, the traditional hoisting and structural construction process needs local adjustment, transformation and innovation to improve the scientificity, accuracy, reliability and safety of the construction. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of hoisting control of the steel cage of the underground continuous wall in the soft sedimentary stratum. A method for hoisting control of the steel cage of the underground continuous wall in the soft sedimentary stratum is proposed.

[0005] The purpose of the present invention can be achieved by adopting the following technical solutions: A method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum comprises the following steps: Production of S101 underground continuous wall reinforcement cage; The manufacturing of the underground continuous wall reinforcement cage includes manufacturing the underground continuous wall reinforcement cage according to the design requirements of the underground continuous wall; Installation of S102 monitoring points; The installation of the monitoring points includes arranging n horizontal monitoring sections from the bottom to the top of the right side of the underground continuous wall steel cage according to a fixed height difference H, which are recorded as A1~A n The right side refers to the side of the underground continuous wall reinforcement cage on the right hand side when facing the back soil surface of the underground continuous wall reinforcement cage, and the back soil surface refers to the inner side of the underground continuous wall, and the back soil surface is opposite to the inside of the excavated foundation pit; The installation of the monitoring points also includes the following steps:i , i=1~n arrange 2 monitoring points, and mark them as monitoring point A from the back soil surface of the continuous wall reinforcement cage from near to far. i1 and monitoring point A i2 , the monitoring point is A i1 and monitoring point A i2 The horizontal distance is L; S103 Selection of lifting equipment; The selection of the hoisting equipment includes selecting the hoisting equipment according to the quality of the underground continuous wall steel cage and the hoisting height, and performing a hoisting safety and stability verification analysis according to the selected hoisting equipment. If the hoisting safety and stability verification analysis result meets the requirements, proceed to the next step, otherwise, the hoisting equipment needs to be reselected; S104 started hoisting; The starting of the hoisting includes starting to hoist the continuous wall steel cage using the hoisting equipment. When the continuous wall steel cage is completely vertical to the ground, the hoisting equipment moves steadily to the slot position corresponding to the continuous wall. At this time, the position of the steel cage is confirmed. After the position is confirmed, the steel cage is slowly lowered into the slot. S105 Control during decentralization; The control during the lowering process includes monitoring the horizontal section A at each level during the slow lowering of the continuous wall reinforcement cage into the channel. i , i=1~n The monitoring point A arranged on the section before entering the trench i1 and A i2 The coordinate information of the X, Y and Z directions is obtained by measurement, which are respectively expressed as (X i1 , Y i1 , Z i1 ) and (X i2 , Y i2 , Z i2 ), the X direction is perpendicular to the extension direction of the underground continuous wall, the Y direction is the extension direction of the underground continuous wall, the Z direction is the vertical direction, and the coordinate information is obtained with the measurement reference point set in advance as the origin; The control during the lowering process also includes correcting the position of the lowered continuous wall reinforcement cage based on the obtained coordinate information; S106 completed the hoisting of the continuous wall reinforcement cage; The completion of the hoisting of the continuous wall steel cage includes final confirmation of the position of the steel cage after the steel cage is completely lowered into the channel to ensure that the position, verticality and depth of the steel cage meet the design requirements; The completion of the hoisting of the continuous wall steel cage includes fixing the steel cage to ensure its stability during the subsequent construction process.

[0006] Furthermore, in the above S102, the height difference H is calculated using formula (1): (1) Where H1 is the height of the continuous wall reinforcement cage, and N is the number of monitoring points.

[0007] Furthermore, in the above S102, the horizontal distance L is calculated using formula (2): (2) Where B is the thickness of the continuous wall reinforcement cage, and η is the adjustment coefficient, which ranges from 0.4 to 0.6.

[0008] Furthermore, in the above S105, the method steps for correcting the position of the lowered continuous wall steel cage based on the obtained coordinate information are as follows: a) according to the horizontal monitoring section A of the continuous wall steel cage i Monitoring point A i1 and A i2 The coordinate information of the X, Y and Z directions is obtained by measurement, which are respectively expressed as (X i1 , Y i1 , Z i1 ) and (X i2 , Y i2 , Z i2 b) Check the verticality. If it meets the requirements, proceed to the next step. Otherwise, the continuous wall reinforcement cage needs to be adjusted. The verticality check result is obtained according to formulas (3), (4) and (5). (3) (4) (5) Where H1 is the height of the continuous wall reinforcement cage.

[0009] The beneficial effects of the present invention are: The present invention reduces the possible safety risks, such as hole collapse and bucket jam, when hoisting the steel cage in soft sedimentary strata through precise monitoring and control of the control during the hoisting process of the continuous wall steel cage. By real-time monitoring and correction of the position of the steel cage during the hoisting process, it is ensured that the verticality and position of the steel cage meet the design requirements, thereby improving the construction quality. In the process of hoisting the steel cage, a control standard for the verticality is formulated. At the same time, the control standard for the verticality is combined with the actual situation to formulate a flexible standard for the height of the steel cage, which is more in line with the actual project. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The present invention is a flow chart of a method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum. DETAILED DESCRIPTION

[0011] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings; it should be understood that the specific embodiments given here are only used to illustrate and explain the present invention and cannot be used to limit the present invention.

[0012] The following is a specific embodiment of a method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum.

[0013] In this embodiment, the project is a deep underground foundation pit support construction project. The soil conditions of the project site are: miscellaneous fill, plain fill, silty clay, sandy clay, clay, silty sand, etc. In this site, the initial water level is buried at a depth of 2.00m~2.80mm, and the static water level is buried at a depth of 1.20~2.00m. At the same time, the local deep underground foundation pit support enclosure plan is an underground continuous wall 800mm thick, the first reinforced concrete support is 800mm*1000mm, and the 2nd to 4th are steel pipe inner supports with a diameter of 800mm and a wall thickness of 16mm. The concrete is C35 and the embedded depth is 14.5m.

[0014] During the construction of the foundation pit continuous wall of this project, a method for controlling the lifting of the steel cage of the underground continuous wall in the soft sedimentary stratum was applied. The steps are as follows: Production of S101 underground continuous wall reinforcement cage; The manufacturing of the underground continuous wall reinforcement cage includes manufacturing the underground continuous wall reinforcement cage according to the design requirements of the underground continuous wall; In this project, the typical steel cage number is selected as L-11, and the length of steel cage L-11 is 36m, that is, H1=36m; Installation of S102 monitoring points; The installation of the monitoring points includes arranging n horizontal monitoring sections from the bottom to the top of the right side of the underground continuous wall steel cage according to a fixed height difference H, which are recorded as A1~A n The right side refers to the side of the underground continuous wall reinforcement cage on the right hand side when facing the back soil surface of the underground continuous wall reinforcement cage, and the back soil surface refers to the inner side of the underground continuous wall, and the back soil surface is opposite to the inside of the excavated foundation pit; The installation of the monitoring points also includes the following steps: i , i=1~n arrange 2 monitoring points, and mark them as monitoring point A from the back soil surface of the continuous wall reinforcement cage from near to far. i1 and monitoring point A i2 , the monitoring point is A i1 and monitoring point A i2 The horizontal distance is L; Furthermore, in the above S102, the height difference H is calculated using formula (1): (1) Where H1 is the height of the continuous wall reinforcement cage, and N is the number of monitoring points.

[0015] Furthermore, in the above S102, the horizontal distance L is calculated using formula (2): (2) Where B is the thickness of the continuous wall reinforcement cage, and η is the adjustment coefficient, which ranges from 0.4 to 0.6.

[0016] In this embodiment, the thickness of the continuous wall steel cage L-11 is 0.88m, L=0.5×0.88=0.44m, n=5 horizontal monitoring sections are arranged, recorded as sections A1~A5, the number of monitoring points arranged is N=10, and the calculated height difference H is: H=36 / 6=6m.

[0017] S103 Selection of lifting equipment; The selection of the hoisting equipment includes selecting the hoisting equipment according to the quality of the underground continuous wall steel cage and the hoisting height, and performing a hoisting safety and stability verification analysis according to the selected hoisting equipment. If the hoisting safety and stability verification analysis result meets the requirements, proceed to the next step, otherwise, the hoisting equipment needs to be reselected; In this embodiment, according to the quality of the underground continuous wall steel cage, the lifting height, the layout of the steel cage processing and manufacturing site and the surrounding environment, a double crane is used to lift, and it is determined that the main crane uses a 500T crawler crane with a boom length of 54m, and the auxiliary crane uses a 320T crawler crane with a boom length of 42m; the main crane lifting safety factor verification analysis: when the main crane hoists the steel cage as a whole, the maximum force is when the upper and lower sections of the steel cage are connected and lifted. At this time, the steel cage weighs 120t (according to the heaviest range), the hook weighs 5t, and the rigging weighs 5t, that is, the mass is 120+5+5t=130t; the main crane lifting capacity is 176.6. The main crane lifting safety factor K=130t / 176.6t≈0.74<0.8, which meets the requirements.

[0018] S104 started hoisting; The starting of the hoisting includes starting to hoist the continuous wall steel cage using the hoisting equipment. When the continuous wall steel cage is completely vertical to the ground, the hoisting equipment moves steadily to the slot position corresponding to the continuous wall. At this time, the position of the steel cage is confirmed. After the position is confirmed, the steel cage is slowly lowered into the slot. S105 Control during decentralization; The control during the lowering process includes monitoring the horizontal section A at each level during the slow lowering of the continuous wall reinforcement cage into the channel.i , i=1~n The monitoring point A arranged on the section before entering the trench i1 and A i2 The coordinate information of the X, Y and Z directions is obtained by measurement, which are respectively expressed as (X i1 , Y i1 , Z i1 ) and (X i2 , Y i2 , Z i2 ), the X direction is perpendicular to the extension direction of the underground continuous wall, the Y direction is the extension direction of the underground continuous wall, the Z direction is the vertical direction, and the coordinate information is obtained with the measurement reference point set in advance as the origin; The control during the lowering process also includes correcting the position of the lowered continuous wall reinforcement cage based on the obtained coordinate information; Furthermore, in the above S105, the method steps for correcting the position of the lowered continuous wall steel cage based on the obtained coordinate information are as follows: a) according to the horizontal monitoring section A of the continuous wall steel cage i Monitoring point A i1 and A i2 The coordinate information of the X, Y and Z directions is obtained by measurement, which are respectively expressed as (X i1 , Y i1 , Z i1 ) and (X i2 , Y i2 , Z i2 b) Check the verticality. If it meets the requirements, proceed to the next step. Otherwise, the continuous wall reinforcement cage needs to be adjusted. The verticality check result is obtained according to formulas (3), (4) and (5). (3) (4) (5) Where H1 is the height of the continuous wall reinforcement cage.

[0019] In this embodiment, H1=36m, and the equation (5) is used to obtain θ 标准 =3~4°, in this embodiment, 4° is taken, the monitoring point data obtained from the horizontal monitoring sections A1~A5 and the verticality verification results are shown in Table 1, and all sections of the steel cage L-11 have passed the verticality verification; Table 1 Calculation results of verticality of steel cage L-11

[0020] S106 completed the hoisting of the continuous wall reinforcement cage; The completion of the hoisting of the continuous wall steel cage includes final confirmation of the position of the steel cage after the steel cage is completely lowered into the channel to ensure that the position, verticality and depth of the steel cage meet the design requirements; The completion of the hoisting of the continuous wall steel cage includes fixing the steel cage to ensure its stability during the subsequent construction process.

[0021] In the above embodiments, the present invention discloses a method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum; including preliminary preparation, equipment debugging, installation of detection instruments, monitoring of the excavation process, data processing and analysis, and feedback construction; the method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum proposed by the present invention can accurately control the position adjustment of the steel cage based on detection data analysis, thereby reducing the safety risks that may occur when hoisting the steel cage in a soft sedimentary stratum, and can be widely used in the field of underground continuous wall construction.

[0022] The above description is a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum, characterized in that: The following steps are involved: Production of S101 underground continuous wall reinforcement cage; The manufacturing of the underground continuous wall reinforcement cage includes manufacturing the underground continuous wall reinforcement cage according to the design requirements of the underground continuous wall; Installation of S102 monitoring points; The installation of the monitoring points includes arranging n horizontal monitoring sections from the bottom to the top of the right side of the underground continuous wall steel cage according to a fixed height difference H, which are recorded as A1~A n The right side refers to the side of the underground continuous wall reinforcement cage on the right hand side when facing the back soil surface of the underground continuous wall reinforcement cage, and the back soil surface refers to the inner side of the underground continuous wall, and the back soil surface is opposite to the inside of the excavated foundation pit; The installation of the monitoring points also includes the following steps: i , i=1~n arrange 2 monitoring points, and mark them as monitoring point A from the back soil surface of the continuous wall reinforcement cage from near to far. i1 and monitoring point A i2 , the monitoring point is A i1 and monitoring point A i2 The horizontal distance is L; S103 Selection of lifting equipment; The selection of the hoisting equipment includes selecting the hoisting equipment according to the quality of the underground continuous wall steel cage and the hoisting height, and performing a hoisting safety and stability verification analysis according to the selected hoisting equipment. If the hoisting safety and stability verification analysis result meets the requirements, proceed to the next step, otherwise, the hoisting equipment needs to be reselected; S104 started hoisting; The starting of the hoisting includes starting to hoist the continuous wall steel cage using the hoisting equipment. When the continuous wall steel cage is completely vertical to the ground, the hoisting equipment moves steadily to the slot position corresponding to the continuous wall. At this time, the position of the steel cage is confirmed. After the position is confirmed, the steel cage is slowly lowered into the slot. S105 Control during decentralization; The control during the lowering process includes monitoring the horizontal section A at each level during the slow lowering of the continuous wall reinforcement cage into the channel. i , i=1~n The monitoring point A arranged on the section before entering the trench i1 and A i2 The coordinate information of the X, Y and Z directions is obtained by measurement, which are respectively expressed as (X i1 , Y i1 , Z i1 ) and (X i2 , Y i2 , Z i2 ), the X direction is perpendicular to the extension direction of the underground continuous wall, the Y direction is the extension direction of the underground continuous wall, the Z direction is the vertical direction, and the coordinate information is obtained with the measurement reference point set in advance as the origin; The control during the lowering process also includes correcting the position of the lowered continuous wall reinforcement cage based on the obtained coordinate information; S106 completed the hoisting of the continuous wall reinforcement cage; The completion of the hoisting of the continuous wall steel cage includes final confirmation of the position of the steel cage after the steel cage is completely lowered into the channel to ensure that the position, verticality and depth of the steel cage meet the design requirements; The completion of the hoisting of the continuous wall steel cage includes fixing the steel cage to ensure its stability during the subsequent construction process.

2. The method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum according to claim 1 is characterized in that: In S102, the height difference H is calculated using formula (1): （1） Where H1 is the height of the continuous wall reinforcement cage, and N is the number of monitoring points.

3. The method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum according to claim 1 is characterized in that: In S102, the horizontal distance L is calculated using formula (2): （2） Where B is the thickness of the continuous wall reinforcement cage, and η is the adjustment coefficient, which ranges from 0.4 to 0.

6.

4. The method for controlling the hoisting of a steel cage of an underground continuous wall in a soft sedimentary stratum according to claim 1 is characterized in that: In the step S105, the method steps for correcting the position of the lowered continuous wall steel cage based on the obtained coordinate information are as follows: a) according to the horizontal monitoring section A of the continuous wall steel cage, i Monitoring point A i1 and A i2 The coordinate information of the X, Y and Z directions is obtained by measurement, which are respectively expressed as (X i1 , Y i1 , Z i1 ) and (X i2 , Y i2 , Z i2 b) Check the verticality. If it meets the requirements, proceed to the next step. Otherwise, the continuous wall reinforcement cage needs to be adjusted. The verticality check result is obtained according to formulas (3), (4) and (5). （3） （4） （5） Where H1 is the height of the continuous wall reinforcement cage.

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