Optimized construction method of composite stratum slurry shield based on BIM technology

Abstract

The invention discloses a composite stratum slurry shield optimization construction method based on BIM technology, which belongs to the technical field of tunnel construction optimization, solves the technical problems that traditional technologies cannot realize real-time tracking, early warning and monitoring during shield construction, and the intelligence level is not high, and comprises: S1: surveying the composite stratum and obtaining the three-dimensional coordinates of the area; S2: sampling the composite stratum separately, and detecting the rock and soil particle size and stratum permeability of each soil layer in the composite stratum; S3: selecting a shield machine according to the detection result in step S2; S4: performing a cutterhead opening rate experiment at a construction site according to the selected shield machine, completing the cutterhead update optimization, realizing real-time tracking, early warning and monitoring of the tunnel construction process, and realizing the intelligence of the tunnel construction process.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction optimization, and in particular to a composite stratum slurry shield optimization construction method based on BIM technology. Background Art

[0002] With the continuous development of urban rail transit construction, it is inevitable to build a large number of shield subway tunnels in composite strata, but there are few examples of slurry shield applications in urban rail transit. At the same time, the construction process of slurry shield in composite strata subway tunnels lacks scientific judgment indicators, and the intelligent detection technology for composite strata tunnels is relatively weak, which makes it impossible to achieve real-time tracking, early warning and monitoring during shield construction.

[0003] In view of the above-mentioned deficiencies in the existing technologies, how to achieve safe and efficient subway tunnel construction under complex stratum conditions and how to realize the intelligent application of BIM technology are urgent issues that need to be solved. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides an optimized construction method for a composite stratum slurry shield based on BIM technology, which solves the technical problems in the prior art that real-time tracking, early warning and monitoring during shield construction cannot be achieved and the degree of intelligence is not high.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] A composite stratum slurry shield optimization construction method based on BIM technology includes the following steps:

[0007] S1: Survey the composite stratum and obtain the three-dimensional coordinates of the area;

[0008] S2: sampling the composite stratum separately and testing the rock and soil particle size and stratum permeability of each soil layer in the composite stratum;

[0009] S3: Selecting a shield machine according to the detection result in step S2;

[0010] S4: Conduct cutterhead opening rate experiments at the construction site based on the selected shield machine and complete cutterhead update and optimization;

[0011] S5: Using the BIM platform, a three-dimensional construction model diagram of the tunnel under the composite stratum condition is drawn according to the three-dimensional coordinates in step S1, and the model diagram is implanted into the finite element numerical simulation software, and the optimal slurry shield steel sleeve starting and receiving construction plan is obtained through the orthogonal experimental method;

[0012] S6: Several sensor devices are set up at the construction site, where the sensors are connected to the BIM platform via Internet signals. The BIM platform optimizes the slurry shield construction method in the composite stratum tunnel based on the data measured by the sensors.

[0013] By adopting the above scheme, step S5 can complete the formulation of the optimal construction scheme for the slurry shield steel casing starting and receiving by finite element numerical simulation software, which specifically includes implanting the three-dimensional construction model diagram of the tunnel under the composite formation conditions into the finite element numerical simulation software, and selecting the construction parameters by the orthogonal experimental method. After the above construction parameters are input into the finite element numerical simulation software, various working conditions can be simulated, and the optimal scheme that can meet the construction conditions is the optimal scheme; in the above step S6, various parameters in the tunnel construction can be monitored in real time by several sensor devices, and the sensor devices can transmit the above parameters to the BIM platform through the Internet. The BIM platform can formulate and optimize the construction scheme according to the obtained data, and provide real-time tunnel parameters for construction personnel. Through the above scheme, real-time monitoring of the situation during the tunnel construction is realized, and the construction method is continuously optimized according to the changes in the tunnel, so as to realize the intelligence of tunnel construction and real-time tracking, monitoring and early warning of the tunnel construction situation.

[0014] Furthermore, the soil layers sampled in the composite stratum include a warm stone layer, a coarse gravel layer, a medium-fine gravel layer, a silt-fine gravel layer, a coarse sand layer, a silt-fine sandstone, a mud-sandstone and a clay layer.

[0015] By adopting the above scheme, by sampling each soil layer in the above composite stratum, it is possible to comprehensively monitor the physical properties of the composite stratum, thereby optimizing the model of the slurry shield machine and improving the cutterhead.

[0016] The specific steps of step S3 are:

[0017] S31: Detect the permeability parameters of each soil layer in the composite stratum. When the permeability parameter is ≥10 -7 m / s, a mud-water pressure shield machine is selected; when the permeability parameter is less than 10 -7 m / s, an earth pressure balance shield machine is selected;

[0018] S32: Detect the particle size in the composite stratum and stratify the soil layers according to the particle size. When the ratio of the sum of the number of silt gravel layers and silt sandstone to the number of clay layers is ≥40%, use an earth pressure balance shield machine; when the ratio of the sum of the number of silt gravel layers and silt sandstone to the number of clay layers is <40%, use a slurry pressure shield machine.

[0019] By adopting the above scheme, the shield machine can be selected according to the particle size and permeability parameters of each soil layer in the composite stratum, and the shield machine can be accurately selected based on the actual situation of the composite stratum.

[0020] Furthermore, the particle size of the clay layer is 0.001 mm, and the particle size of the fine gravel layer and the fine sandstone is greater than 0.075 mm.

[0021] Furthermore, the specific steps of step S4 are: conducting an opening rate experiment, if the time for flushing the cutter disc mud cake during the cutter change operation is ≥ 30% of the total cutter change time, then increasing the opening area of ​​the cutter disc or the flushing system of the spokes.

[0022] For the cutterhead with a smaller opening ratio in the slurry shield machine, the low opening ratio in the center and the inappropriate form of the slag diversion port will cause the formation of "mud cake" in the center of the cutterhead during excavation in muddy sandstone and mudstone formations. If the time for flushing the cutterhead mud cake accounts for 30%-40%, it means that the opening ratio of the cutterhead is too low or the flushing system is too small, resulting in low mud cake cleaning efficiency. The above time ratio is the critical value of the cutterhead mud cake flushing time. In this scheme, the optimization method of the cutterhead is to increase the flushing system of the cutterhead and the spokes until the time for flushing the cutterhead mud cake is less than 30% of the total cutter change time. Through the above scheme, a method and critical value for detecting the cutterhead opening ratio by detecting the mud cake flushing time are provided, which provides a reference for construction personnel on whether the opening ratio and flushing system need to be increased.

[0023] Furthermore, the slurry shield machine performs advance support when passing through composite strata, wherein the support spacing is 3-5m.

[0024] When the above scheme is adopted, when the surrounding rock is broken in the tunnel, the excavation disturbance will cause a large deformation of the surrounding rock. If the advance support measures are not timely, the surrounding rock deformation may exceed its allowable range. In severe cases, it will cause the instability of the heading face and the collapse of the tunnel, resulting in significant economic losses. Therefore, this scheme adopts tunnel advance support measures to control the deformation of the surrounding rock, so as to achieve the purpose of ensuring the safety of tunnel construction.

[0025] Furthermore, the sensing device includes a stress sensor, a displacement sensor and an angle sensor, which respectively perform stress monitoring, settlement monitoring and inclination monitoring.

[0026] Furthermore, stress sensors are embedded in the surrounding rock of the tunnel, displacement sensors are arranged at the top and both sides of the tunnel, and angle sensors are arranged in the middle of the top of the tunnel.

[0027] By adopting the above scheme, the detection accuracy and detection environment requirements of each sensor can be guaranteed.

[0028] Furthermore, the specific steps of S5 are:

[0029] Step S51: After obtaining the three-dimensional numerical model, meshing is performed using HYpermesh software and output to finite element software ANSYS;

[0030] Step S52: The orthogonal experimental method is used to select the technical parameters for the launching and receiving construction of the slurry shield, and a working condition simulation test is performed in ANSYS based on the above parameters.

[0031] By adopting the above scheme, simulation tests of various working conditions can be carried out through ANSYS to detect whether the construction technical parameters obtained by the orthogonal experimental method can meet the construction requirements.

[0032] Furthermore, the working condition simulation test in S52 includes simulation test of steel sleeve launching device, backfilling in steel sleeve and pressure test.

[0033] By adopting the above scheme, through the advance working condition simulation in ANSYS software, it can be predicted whether the connection between the steel sleeve and the tunnel ring plate and the sealing of the steel sleeve assembly seam can remain intact during the construction process under the above construction parameters; the backfill and pressure test in the steel sleeve can detect whether the pressure can be maintained unchanged for 5 hours after the pressure of the soil chamber reaches the test pressure value by injecting mud into the soil chamber. This method can further improve the efficiency of construction scheme optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the process of the present invention;

[0035] Figure 2 It is a schematic diagram of the composite formation structure of the present invention;

[0036] Figure 3 It is a schematic diagram of the relationship between the shield machine type and the permeability parameters of the present invention;

[0037] Figure 4 It is a schematic diagram of the particle size of each soil layer of the present invention.

[0038] Figure numerals: 101 - warm stone layer; 102 - coarse gravel layer; 103 - medium-fine gravel layer; 104 - fine gravel layer; 105 - coarse sand layer; 106 - fine sandstone; 107 - mudstone; 108 - clay layer. DETAILED DESCRIPTION

[0039] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0040] Embodiment 1:

[0041] In this embodiment, a method for real-time tracking, early warning and monitoring of the construction process is provided, thereby improving the safety of the construction process. In this process, the received tunnel information is processed in real time through the BIM platform to obtain an optimal construction plan, which is specifically:

[0042] A composite stratum slurry shield optimization construction method based on BIM technology includes the following steps:

[0043] S1: Survey the composite stratum and obtain the three-dimensional coordinates of the area;

[0044] S2: sampling the composite stratum separately and testing the rock and soil particle size and stratum permeability of each soil layer in the composite stratum;

[0045] S3: Selecting a shield machine according to the detection result in step S2;

[0046] S4: Conduct cutterhead opening rate experiments at the construction site and complete cutterhead update and optimization;

[0047] S5: Using the BIM platform, a three-dimensional construction model diagram of the tunnel under the composite stratum condition is drawn according to the three-dimensional coordinates in step S1, and the model diagram is implanted into the finite element numerical simulation software, and the optimal slurry shield steel sleeve starting and receiving construction plan is obtained through the orthogonal experimental method;

[0048] S6: Several sensor devices are set up at the construction site, where the sensors are connected to the BIM platform via Internet signals. The BIM platform optimizes the slurry shield construction method in the composite stratum tunnel based on the data measured by the sensors.

[0049] Steps S1-S3 are the shield machine selection and cutterhead optimization process, step S5 is the optimization process of the technical parameters before construction and the slurry shield steel sleeve starting and receiving construction plan, and step S6 is the process of construction, in which the sensor monitors the tunnel conditions in real time and transmits the detected data to the BIM platform via the Internet. The BIM platform can obtain the optimal construction plan based on its own computing simulation capabilities. The construction plan can be adaptively changed according to changes in tunnel conditions. Through this plan, the intelligentization of the slurry shield machine tunnel construction process and real-time monitoring of the tunnel construction process can be realized. The flowchart of the work of this system is as follows Figure 1 shown.

[0050] In the above composite stratum, the main soil layers sampled include warm rock layer 101, coarse gravel layer 102, medium-fine gravel layer 103, fine gravel layer 104, coarse sand layer 105, fine sandstone 106, mud sandstone 107 and clay layer 108. The specific structure of the composite stratum is as follows: Figure 2As shown, by detecting the particle size and permeability of the soil layer, the shield machine can be selected, which is specifically achieved through step S3:

[0051] The specific steps of step S3 are:

[0052] S31: Detect the permeability parameters of each soil layer in the composite stratum. When the permeability parameter is ≥10 -7 m / s, use a mud-water pressure shield machine. When the permeability parameter is less than 10 -7 m / s, an earth pressure balance shield machine is selected;

[0053] S32: Detect the particle size in the composite stratum and stratify the composite stratum according to the particle size. When the ratio of the sum of the number of the silt gravel layer 104 and the silt sandstone 106 to the number of the clay layer 108 is ≥40%, select an earth pressure balance shield machine; when the ratio of the sum of the number of the silt gravel layer 104 and the silt sandstone 106 to the number of the clay layer 108 is <40%, select a slurry pressure shield machine.

[0054] In the above scheme, considering that the requirements of the slurry pressure shield machine on the soil layer are higher than those of the earth pressure balance shield machine, the minimum permeability parameter of the soil layer in the composite stratum is ≥10 -7 m / s, a slurry pressure shield machine is selected, otherwise an earth pressure balance shield machine is selected; in the above step S32, the ratio of the amount of fine gravel layer 104 and fine sandstone 106 in the composite stratum to the amount of clay layer 108 is used as a reference. When the ratio is ≥40%, an earth pressure balance shield machine is selected, otherwise a slurry pressure shield machine is selected. The schematic diagram of permeability parameters and shield machine model selection is shown in Figure 3 As shown, the amount of fine gravel layer 104 and fine sandstone 106 in the composite formation is the total amount of silt and clay in the rock and soil.

[0055] The particle size of the clay layer in the composite stratum is 0.001 mm, and the particle size of the fine gravel layer and fine sandstone is greater than 0.075 mm. When calculating, the above standards are used as reference values. The particle sizes of the various soil layers in the composite stratum are as follows: Figure 4 shown.

[0056] In this embodiment, a detection standard for whether the cutter disc needs to be optimized is provided, specifically, by calculating the time ratio of the mud cake flushing during the cutter change process to determine whether it is necessary to increase the cutter disc opening rate and add a flushing system, which is specifically achieved through the above step S4, wherein the specific steps of step S4 are: conducting an opening rate experiment, if the time of flushing the cutter disc mud cake during the cutter change operation is ≥ 30% of the total cutter change time, then adding the flushing system of the cutter disc and the spokes. Increasing the opening area of ​​the cutter disc can increase the cutter disc opening rate, thereby reducing the amount of mud cake formed in the center of the cutter disc.

[0057] In this embodiment, in order to prevent the face from becoming unstable and causing landslides, advance support is carried out when the slurry shield machine passes through composite strata, wherein the support spacing is 3-5m. The above-mentioned advance support is an auxiliary measure taken ahead of the face excavation to ensure the stability of the tunnel excavation working face, which can ensure the safety during tunnel construction.

[0058] The above-mentioned sensing device includes a stress sensor, a displacement sensor and an angle sensor, which respectively perform stress monitoring, settlement monitoring and inclination monitoring.

[0059] The stress sensor is embedded in the tunnel surrounding rock, the displacement sensor is set at the top and both sides of the tunnel, and the angle sensor is set in the middle of the tunnel top.

[0060] By using the above-mentioned sensor devices and setting the sensor devices at corresponding positions in the tunnel, it is possible to form a comprehensive monitoring of the tunnel and realize real-time tracking and early warning of the construction progress.

[0061] As mentioned above, in this embodiment, the slurry shield steel sleeve launching and receiving construction technology can be optimized, which is specifically achieved through the above step S5, wherein the specific steps of step S5 are:

[0062] Step S51: After obtaining the three-dimensional numerical model, meshing is performed using HYpermesh software and output to finite element software ANSYS;

[0063] Step S52: The orthogonal experimental method is used to select the technical parameters for the launching and receiving construction of the slurry shield, and a working condition simulation test is performed in ANSYS based on the above parameters.

[0064] Through the above scheme, the construction technical parameters obtained in the orthogonal experimental method can be simulated and tested, and the current construction plan can be optimized. The simulation test includes the simulation test of the steel sleeve starting device, the backfilling and pressure test in the steel sleeve. The simulation test of the steel sleeve starting device is to check whether the connection between the steel sleeve and the tunnel ring plate and the steel sleeve assembly seam are sealed. This simulation test can detect whether the input construction parameters meet the construction requirements;

[0065] The steel sleeve backfill and pressure test tests simulate the injection of water into the soil tank to make the pressure in the soil tank reach the test pressure value, and observe whether the pressure can be maintained unchanged for 5 hours. In the above two tests, the lowest pressure resistance parameter of the steel sleeve is set to 6 bar.

Claims

1. A composite stratum slurry shield optimization construction method based on BIM technology, characterized in that: The following steps are involved: S1: Survey the composite stratum and obtain the three-dimensional coordinates of the area; S2: sampling the composite stratum separately and testing the rock and soil particle size and stratum permeability of each soil layer in the composite stratum; S3: Selecting a shield machine according to the detection result in step S2; S4: Conduct cutterhead opening rate experiments at the construction site based on the selected shield machine and complete cutterhead update and optimization; The specific steps are: conduct an opening rate experiment. If the time for flushing the mud cake of the cutter disc during the cutter change operation is ≥ 30% of the total cutter change time, increase the opening area of ​​the cutter disc or the flushing system of the spokes; S5: Through the BIM platform, a three-dimensional construction model diagram of the tunnel under the composite stratum condition is drawn according to the three-dimensional coordinates in step S1, and the model diagram is implanted into the finite element numerical simulation software, and the optimal slurry shield steel sleeve starting and receiving construction plan is obtained through the orthogonal experimental method; the specific steps are: Step S51: After obtaining the three-dimensional numerical model, meshing is performed using HYpermesh software and output to finite element software ANSYS; Step S52: selecting the technical parameters for the launching and receiving construction of the slurry shield by the orthogonal experimental method, and performing a working condition simulation test based on the above parameters in ANSYS; the working condition simulation test includes a simulation test of the steel sleeve launching device, backfilling in the steel sleeve, and a pressure test; S6: Several sensor devices are set up at the construction site, where the sensors are connected to the BIM platform via Internet signals. The BIM platform optimizes the slurry shield construction method in the composite stratum tunnel based on the data measured by the sensors.

2. The optimized construction method of composite stratum slurry shield based on BIM technology according to claim 1 is characterized in that: The soil layers sampled in the composite stratum include a warm stone layer (101), a coarse gravel layer (102), a medium-fine gravel layer (103), a fine gravel layer (104), a coarse sand layer (105), fine sandstone (106), mudstone (107) and a clay layer (108).

3. The optimized construction method of composite stratum slurry shield based on BIM technology according to claim 2 is characterized in that: The specific steps of step S3 are: S31: Detect the permeability parameters of each soil layer in the composite stratum. When the permeability parameter is ≥10 -7 m / s, a mud-water pressure shield machine is selected; when the permeability parameter is less than 10 -7 m / s, an earth pressure balance shield machine is selected; S32: Detect the particle size in the composite stratum and stratify the composite stratum according to the particle size. When the ratio of the amount of the silt gravel layer (104) and the silt sandstone (106) to the amount of the clay layer (108) is ≥40%, select an earth pressure balance shield machine; when the ratio of the amount of the silt gravel layer (104) and the silt sandstone (106) to the amount of the clay layer (108) is <40%, select a slurry pressure shield machine.

4. The optimized construction method of composite stratum slurry shield based on BIM technology according to claim 3 is characterized in that: The particle size of the clay layer (108) is 0.001 mm, and the particle sizes of the fine gravel layer (104) and the fine sandstone (106) are greater than 0.075 mm.

5. The optimized construction method of composite stratum slurry shield based on BIM technology according to claim 1 is characterized in that: The shield machine performs advance support when passing through composite strata, wherein the support spacing is 3-5m.

6. The optimized construction method of composite stratum slurry shield based on BIM technology according to claim 1 is characterized in that: The sensing device comprises a stress sensor, a displacement sensor and an angle sensor, which respectively perform stress monitoring, settlement monitoring and inclination monitoring.

7. The optimized construction method of composite stratum slurry shield based on BIM technology according to claim 6 is characterized in that: The stress sensor is pre-buried in the surrounding rock of the tunnel, the displacement sensor is arranged at the top and both sides of the tunnel, and the angle sensor is arranged in the middle of the top of the tunnel.

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