A shield parameter adjustment method, support device and starting end drilling method

Abstract

The present invention relates to the technical field of shield construction, and specifically, discloses a shield parameter adjustment method, a support device, and a starting end drilling method. The adjustment method includes S1, trial excavation section division; S2, first stage trial excavation parameter adjustment; S3, second stage trial excavation parameter adjustment; S4, third stage trial excavation parameter adjustment; S5, fourth stage trial excavation parameter adjustment; it can ensure the construction safety and quality of subsequent excavation. The support device includes a device body, the device body includes a first support rod and a reaction frame, the reaction frame includes a vertical rod and a connecting rod; the first support rod is provided with a second support rod and a third support rod at one end close to the reaction frame; it can better improve the support strength of the reaction frame. The drilling method includes S1, starting end reinforcement; S2, shield machine drilling parameter adjustment; it can ensure that the shield machine can drill smoothly after passing through the starting end.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, in particular to a shield parameter adjustment method, a supporting device and a starting end drilling method. Background Art

[0002] Shield construction is widely used in underground projects such as subways and tunnels. The adjustment of its excavation parameters directly affects the construction progress, cost and safety. Traditional shield parameter adjustment methods mostly rely on manual experience, and have problems such as low adjustment accuracy and slow response speed. Summary of the Invention

[0003] The present invention provides a shield parameter adjustment method, a supporting device and an initial end drilling method, which can overcome certain defects of the prior art.

[0004] According to a shield parameter adjustment method of the present invention, the steps are as follows:

[0005] S1. Division of trial excavation section

[0006] Starting from the starting end of the shield machine, 0-9 meters is divided into the first stage of trial excavation, 9-20 meters is divided into the second stage of trial excavation, 20-30 meters is divided into the third stage of trial excavation, and 30-50 meters is divided into the fourth stage of trial excavation.

[0007] S2. Adjustment of parameters for the first stage of trial excavation

[0008] During shield machine excavation, since the first stage is the reinforcement area, the shield machine's posture is controlled to keep the horizontal deviation between +20 and -20 mm, the horizontal trend between 0 and 1 mm, the vertical deviation between +20 and -20 mm, and the vertical trend between -5 and 5 mm. In the shield machine excavation parameters, the total thrust of the jack is set to less than 8000 kN, and the support point of the jack is set at the shield support device, which provides the jack with the driving force. Then, the cutterhead torque is set to less than 2000 kN.m, the cutterhead speed is maintained between 0.8 and 1.0 rpm, the excavation speed is controlled at less than 10 mm / min, and the soil bin pressure is maintained between 0 and 1.0 bar.

[0009] S3. Adjustment of parameters for the second stage of trial excavation

[0010] After the first phase of trial excavation, the shield passed through the reinforced area and entered the soil smoothly, and earth pressure balance was basically established. After the shield machine entered the soil, the total thrust of the jacks was adjusted to maintain at 10,000 kN. At this time, the shield machine excavation speed was increased to maintain at 20-30 mm / min. The horizontal deviation of the shield machine was adjusted to -30-+30 mm, and the horizontal trend was controlled at 0-1 mm. The vertical deviation was controlled between -30-+20 mm, and the vertical trend was controlled between -5-5 mm. The cutterhead torque was controlled at less than 2500 kN.m, the cutterhead speed was controlled at 1.0-1.2 rpm, and the soil bin pressure was controlled at 1.0-1.5 bar. After the shield passed through the reinforced area, grouting was carried out in the soil layer around the shield, with the grouting pressure controlled at 0.25 MPa and the grouting volume controlled at 4 m³.

[0011] S4. Adjustment of parameters for the third stage of trial excavation

[0012] Based on the excavation parameters of the second phase, the excavation parameters of the third phase were further adjusted. The shield thrust was set at 11,000 kN. The cutterhead speed was increased to 1.2-1.3 rpm, the shield excavation speed was increased to 30-40 mm / min, and the soil bin pressure was controlled at 1.3-1.6 bar. The shield machine's horizontal deviation, horizontal trend, vertical deviation, vertical trend, grouting pressure, and grouting volume remained the same as those of the second phase.

[0013] S5. Adjustment of parameters for the fourth stage of trial excavation

[0014] The horizontal deviation of the shield machine is controlled between -50 and +50 mm, the vertical deviation is controlled between -50 and +50 mm, the total thrust of the jack is controlled at 13,000 KN, the cutterhead torque is controlled at 3,000 KN.m, the cutterhead speed is controlled at 1.0 to 1.2, the excavation speed is controlled at 30 to 50 mm / min, and the other parameters are the same as those in the third stage.

[0015] Through the present invention, trial excavation can comprehensively test the overall performance of the shield machine, such as propulsion force, torque, etc., to ensure that it meets the construction requirements; by dividing the trial excavation section into the first trial excavation stage, the second trial excavation stage, the third trial excavation stage and the fourth trial excavation stage, the excavation parameters of the shield machine in different stages are gradually adjusted and optimized, thereby ensuring the construction safety and quality of subsequent excavation.

[0016] During the shield machine's initial reinforcement section, the total thrust of the jack is set to less than 8,000 kN, the cutterhead torque is set to less than 2,000 kN.m, the cutterhead speed is maintained between 0.8 and 1.0 rpm, the excavation speed is controlled at less than 10 mm / min, and the soil bin pressure is maintained between 0 and 1.0 bar. The low-thrust mode ensures high construction safety, especially in complex geological environments or where there are uncertainties. Lower thrust helps reduce potential risks.

[0017] After the shield machine successfully passes through the reinforced area and enters the soil, although increasing the thrust can increase the excavation speed, excessive thrust may lead to enhanced interaction between the shield machine and the surrounding soil, thereby increasing construction risks; therefore, the total thrust of the jack is maintained at 10,000KN, which not only ensures excavation efficiency but also avoids potential risks caused by excessive thrust.

[0018] The excavation parameters of the third and fourth stages are further increased until the shield machine passes through the trial excavation section, thereby obtaining reasonable parameters for the shield machine to drill in subsequent strata.

[0019] Preferably, when the shield machine enters the reinforcement area of ​​the first stage, the cutter head torque is increased and foam is injected in front of the excavation chamber.

[0020] Through the present invention, long-term excavation will cause tool wear and reduced cutting efficiency, which in turn increases the cutter head torque. By injecting foam to lubricate the surface of soil particles, the soil flow plasticity is improved, and the cutter head torque is reduced. The foam can effectively prevent the debris from sticking to the cutter head, reduce the formation of mud cakes, keep the cutter head clean, and improve work efficiency.

[0021] As a preference, during the tunneling process of the shield machine, the segments are lined behind the shield machine. The segments shall not have internal or external penetrating cracks, and shall not have cracks with a width greater than 0.2 mm and concrete spalling during the use stage.

[0022] Through the present invention, cracks and spalling can easily reduce the bearing capacity of the pipe segments and increase the risk of tunnel collapse; cracks and spalling can destroy the waterproof layer of the pipe segments, causing water leakage in the tunnel, affecting the normal use and durability of the tunnel.

[0023] As a preference, during the starting process of the shield machine, grease should be injected at the shield tail wire brush position.

[0024] Through the present invention, injecting grease into the shield tail can form a pressure-sealed chamber, effectively preventing the infiltration of groundwater, mud, etc., and improving the safety of the excavation process.

[0025] As a preference, during the shield machine excavation process, synchronous grouting and secondary grouting control need to be implemented. Synchronous grouting is carried out simultaneously with shield excavation. A grouting machine and a grouting pipe are used to pass through the pipe segment and grout the soil layer outside the pipe segment. Secondary grouting control is carried out two or more times of backfill grouting according to the actual project conditions, such as pipe segment leakage, tunnel settlement, etc.

[0026] Through the present invention, synchronous grouting can ensure the early and late stability of the segment lining by injecting slurry evenly and densely; secondary or multiple backfill grouting can make up for the part not filled by the first grouting and fill the gap caused by slurry shrinkage; prevent the expansion of the surrounding stratum relaxation range and enhance the stability of the stratum.

[0027] Preferably, elastic sealing gaskets are added at the interfaces between the segments, and the dimensional accuracy of the elastic sealing gaskets is as follows: height tolerance +0.5mm; maximum width tolerance ±1.0mm; top surface width tolerance ±1.0mm; foot width tolerance ±1.0mm; and aperture tolerance ±0.2mm.

[0028] Through the present invention, the elastic sealing gasket can effectively fill the gaps between the pipe segments, prevent the infiltration of impurities such as soil and water, and ensure the overall sealing of the tunnel.

[0029] The present invention provides a shield support device, which is used in S2 to S5 of a shield parameter adjustment method, and includes a device main body, which includes a first support rod arranged along the length direction of the shield machine starting shaft and located on both sides of the shield machine track; a reaction frame perpendicular to the first support rod is provided at one end of the first support rod, and the reaction frame includes two vertical rods perpendicular to the first support rod, and the upper and lower ends of the two vertical rods are each provided with a connecting rod for connecting the two vertical rods; an end of the first support rod close to the reaction frame is provided with an inclined second support rod, and an end of the second support rod away from the first support rod is provided with a third support rod arranged parallel to the first support rod; a first oblique support rod inclined between the second support rod and the vertical rod is provided, and a second oblique support rod is provided between the third support rod and the vertical rod.

[0030] Through the present invention, the device body is arranged in the starting shaft and is located behind the shield machine. The starting shaft of the shield machine is connected to the previous tunnel. The shield machine needs to use the rear jack to provide thrust during the starting process. Before the shield machine starts, a track is first laid at the bottom of the starting shaft, and then two first support rods, a second support rod and a third support rod are arranged on both sides of the track along the length direction of the starting shaft. Then, the reaction frame is welded or vertically fixed on the two first support rods by bolts, and then the first diagonal support rod is installed between the vertical rod and the second support rod, so that the two ends of the first diagonal support rod are welded to the vertical rod and the second support rod; the second support rod is inclined to increase the supporting force of the second support rod, thereby preferably increasing the supporting strength of the reaction frame; after the first diagonal support rod is connected, the two ends of the second diagonal support rod are respectively welded to the vertical rod and the third support rod, and the reaction frame is supported by the second diagonal support rod, thereby further strengthening the overall supporting strength of the reaction frame.

[0031] Preferably, a third oblique support rod is provided between the connecting rod and the vertical rod; and a support ring fixedly connected to the connecting rod, the vertical rod and the third oblique support rod is provided at one end face of the reaction frame away from the second oblique support rod.

[0032] Through the present invention, the jack at the rear of the shield machine rests on the support ring, the support ring presses on the reaction frame, and the third diagonal support rod is located between the connecting rod and the vertical rod, thereby better improving the overall structural strength of the reaction frame; at the same time, the support ring rests on the connecting rod, the vertical rod and the third diagonal support rod, thereby increasing the contact area between the support ring and the reaction frame, preventing the reaction frame from being deformed due to uneven force when the support ring rests on the reaction frame when pressure is applied by the jack.

[0033] Preferably, a support plate for connecting the two first support rods is provided at the connection between the second support rod and the first support rod; a plurality of first support blocks arranged at intervals along the length direction of the connecting rod and extending toward the support plate are provided at the connecting rod located at the lower end of the vertical rod; a plurality of second support blocks arranged at intervals along the length direction of the connecting rod are provided at the connecting rod located at the upper end of the vertical rod.

[0034] Through the present invention, the first support block rests on the support plate, and the second support block rests on the top of the tunnel connected to the starting well. Through the joint support of the first support block, the support plate and the second support block, the overall structural strength and support strength of the device body are further enhanced.

[0035] Through the joint action of the second diagonal support rod, the first diagonal support rod, the second support rod, the first support block and the second support block, the overall structural strength and support strength of the device body are better improved; it is prevented that during the trial excavation section of the shield machine, the total thrust of the jack needs to be gradually increased during the excavation of the trial excavation section of the shield machine, which leads to insufficient structural strength of the device body, damage to the device body, inability to carry out construction, and affecting the construction progress.

[0036] The present invention provides a shield starting end drilling method, the steps are as follows:

[0037] S1, reinforcement of the origin;

[0038] S2. Adjustment of shield machine drilling parameters.

[0039] According to the present invention, construction workers first lay tracks in the starting well, then hoist the shield machine onto the tracks, and before the shield machine starts drilling, the soil at the front end of the shield machine is reinforced to prevent the ground from collapsing when the shield machine is drilling; during the drilling process at the starting end of the shield machine, various parameters of the shield machine are adjusted to ensure that the shield machine can drill smoothly after passing through the starting end. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the reinforcement structure implemented in step 2.

[0041] Figure 2 Schematic diagram of the device body in implementation 3.

[0042] Figure 3 This is a back view of the device body in implementation 3.

[0043] Figure 4 Schematic diagram of the first support rod in embodiment 3.

[0044] Figure 5 Schematic diagram of the reaction frame for implementing 3.

[0045] Figure 6 This is the back view of the reaction frame implemented in step 3.

[0046] Figure 7 Schematic diagram of the installation position of the limit plate in the implementation of 4.

[0047] Figure 8 Schematic diagram of the implementation of 4 types of limit plates. DETAILED DESCRIPTION

[0048] In order to further understand the content of the present invention, the present invention is described in detail with reference to the embodiments. It should be understood that the embodiments are merely for explanation of the present invention and are not intended to limit the present invention.

[0049] Example 1

[0050] This embodiment provides a shield starting end drilling method, the steps are as follows:

[0051] S1, reinforcement of the origin;

[0052] S2. Adjustment of shield machine drilling parameters.

[0053] Through this embodiment, construction workers first lay tracks in the starting well, and then hoist the shield machine onto the tracks. Before the shield machine starts drilling, the soil at the front end of the shield machine is reinforced to prevent the ground from collapsing when the shield machine drills. During the drilling process at the starting end of the shield machine, various parameters of the shield machine are adjusted to ensure that the shield machine can drill smoothly after passing through the starting end.

[0054] Example 2

[0055] like Figure 1 As shown, this embodiment provides a shield starting end reinforcement structure for reinforcing the starting end of the shield machine, including a portal steel ring 140, a ground-connected wall 130, a first reinforcement area 100, a second reinforcement area 110 and a third reinforcement area 120 arranged in sequence along the forward direction of the shield machine; the third reinforcement area 120 is located in the forward direction of the shield machine, and the second reinforcement area 110 is located above the third reinforcement area 120; the first reinforcement area 100 is located between the second reinforcement area 110, the third reinforcement area 120 and the ground-connected wall 130; the portal steel ring 140 is located on the ground-connected wall 130.

[0056] Through this embodiment, when reinforcing the starting end of the shield machine, if the construction workers detect that the moisture content in the soil layer is small, the freezing method is difficult to implement. In this process, reinforcement is carried out through mixing piles. The mixing piles harden the soft soil into cement-reinforced soil with integrity, water stability and a certain strength through the physical and chemical reaction between cement and soil. In this process, there is less dependence on the moisture in the soil layer. Moreover, when reinforcing through mixing piles, it is only necessary to mix the cement and soil through the drill rod of the drilling rig. However, the freezing method requires the layout of freezing pipelines. The construction process of mixing pile reinforcement is relatively fast, which can effectively shorten the construction period and improve construction efficiency. At the same time, fewer materials and equipment are required, so the overall cost is lower.

[0057] Since the starting end of the shield machine needs to be reinforced, and the position where the shield machine passes through is located in the third reinforcement area 120, when reinforcing the third reinforcement area 120, the cement slurry concentration in the third reinforcement area 120 is greater than the cement slurry concentration in the second reinforcement area 110; thereby making the overall structural strength of the third reinforcement area 120 stronger, which is convenient for the shield machine to pass through; and the cement slurry concentration in the second reinforcement area 110 is relatively weak in order to save materials; reasonable layered reinforcement of the soil layer can effectively save materials, reasonably allocate reinforcement resources, avoid waste, and ensure that the reinforcement effect is optimal.

[0058] The first reinforcement area 100 is reinforced with high-pressure rotary jet piles. The high-pressure rotary jet piles form a high-strength consolidation body through high-pressure jet grouting, thereby improving the shear strength and stability of the foundation and ensuring the safety of the starting end of the shield machine. Since the soil properties in different areas of the starting end of the shield machine are different, mixing piles are suitable for loose soil, while high-pressure rotary jet piles are suitable for hard soil and low porosity. The combination of the two can better adapt to the complex soil conditions at the starting end of the shield machine.

[0059] In this embodiment, the first reinforcement area 100 is reinforced with high-pressure rotary jet piles; the second reinforcement area 110 and the third reinforcement area 120 are reinforced with mixing piles.

[0060] Through this embodiment, since the soil conditions in different areas of the shield machine starting point are different, mixing piles are suitable for loose soil, while high-pressure rotary jet piles are suitable for hard soil with low porosity; the combination of the two can better adapt to the complex soil conditions at the shield machine starting point.

[0061] In this embodiment, the cross-sectional area of ​​the third reinforcement area 120 is larger than the cross-sectional area of ​​the portal steel ring 140 .

[0062] Through this embodiment, the third reinforcement area 120 covers the entire area through which the shield machine passes, so that the shield machine passes inside the third reinforcement area 120 , thereby ensuring that the shield machine can start smoothly and excavate from the third reinforcement area 120 .

[0063] In this embodiment, the reinforcement strength of the third reinforcement area 120 is greater than the reinforcement strength of the second reinforcement area 110 .

[0064] Through this embodiment, the cement slurry concentration in the third reinforcement area 120 is greater than the cement slurry concentration in the second reinforcement area 110; thereby, the overall structural strength of the third reinforcement area 120 is stronger, which is convenient for the shield machine to pass through; and the cement slurry concentration in the second reinforcement area 110 is weaker in order to save materials; reasonable layered reinforcement of the soil layer can effectively save materials, reasonably allocate reinforcement resources, avoid waste, and ensure that the reinforcement effect is optimal.

[0065] In this embodiment, the reinforcement thickness of the first reinforcement area 100 is 0.5-0.6 meters.

[0066] Through this embodiment, a thickness of 0.5 meters can usually meet the requirements of shield construction for foundation stability and ensure the safety of the shield machine's start and excavation; less than 0.5 meters cannot guarantee the safety of the shield machine's start and excavation; and less than 0.6 meters is to avoid material waste.

[0067] In this embodiment, the cross-sectional area of ​​the third reinforcement zone 120 is larger than the cross-sectional area of ​​the tunnel excavated by the shield machine, and the distance between the outer edge of the third reinforcement zone 120 and the outer edge of the tunnel is not less than 0.3 meters.

[0068] Through this embodiment, sufficient spacing helps to reduce risks during the construction process and ensures that the shield machine can advance smoothly.

[0069] This embodiment provides a method for reinforcing the starting end of a shield machine, the steps of which are as follows:

[0070] S1. Mixing pile reinforcement

[0071] At the top of the shield machine launch shaft, multiple pile positions are measured and marked along the shield machine drilling direction and 1,300.5 meters away from the ground connection wall. The drilling rig is then moved to the pile position and started to drill until the hole passes through the shield machine tunnel and exceeds 0.3 meters. During the drilling process, cement slurry is injected and forcibly mixed with the soil to form a cement-soil consolidation body. After mixing is completed, the drilling rig is raised to form a complete mixing pile. The above steps are then repeated to construct the next pile until all piles are completed, forming the second reinforcement area 110 and the third reinforcement area 120.

[0072] S2. High-pressure jet grouting pile reinforcement

[0073] After the mixing pile reinforcement is completed, high-pressure rotary jet pile reinforcement is used between the mixing pile and the ground-connected wall 130; first, the ground is leveled, obstacles are removed, low-lying areas are backfilled and compacted, and slurry drainage ditches are set; then, the pile position is determined using a total station and marked with a nail pile; then, the rotary jet machine is hoisted to the nail pile mark position and the pile driver is calibrated; finally, the slurry is sprayed into the soil at high pressure through the rotary jet machine and mixed with the soil particles; after the mixing is completed, the high-pressure rotary jet pile is formed, forming the first reinforcement area 100.

[0074] Through this embodiment, when the shield machine starting end is reinforced, when the construction workers detect that the moisture content in the soil layer is small, the freezing method is difficult to implement. In this process, reinforcement is carried out through mixing piles. The mixing piles harden the soft soil into cement-reinforced soil with integrity, water stability and a certain strength through the physical and chemical reaction between cement and soil. In this process, there is less dependence on the moisture in the soil layer. And when reinforcement is carried out through mixing piles, it is only necessary to mix the cement and soil through the drill rod of the drilling rig. However, the freezing method requires the layout of freezing pipelines. The construction process of mixing pile reinforcement is relatively fast, which can effectively shorten the construction period and improve construction efficiency. At the same time, fewer materials and equipment are required, so the overall cost is lower.

[0075] The first reinforcement area 100 is reinforced with high-pressure rotary jet piles. The high-pressure rotary jet piles form a high-strength consolidation body through high-pressure jet grouting, thereby improving the shear strength and stability of the foundation and ensuring the safety of the starting end of the shield machine. Since the soil properties in different areas of the starting end of the shield machine are different, mixing piles are suitable for loose soil, while high-pressure rotary jet piles are suitable for hard soil and low porosity. The combination of the two can better adapt to the complex soil conditions at the starting end of the shield machine.

[0076] In this embodiment, the total reinforcement length of the first reinforcement area 100 , the second reinforcement area 110 , and the third reinforcement area 120 is greater than 9 meters.

[0077] Through this embodiment, the reinforcement length greater than 9 meters can ensure that the shield machine will not deflect or collapse due to unstable strata when it starts.

[0078] In this embodiment, in S1, when the second reinforcement area 110 and the third reinforcement area 120 are reinforced, the third reinforcement area 120 is reinforced first and then the second reinforcement area 110; when the drill rod drills into the third reinforcement area 120, cement slurry is injected and forcibly mixed with the soil. After the cement slurry in the third reinforcement area 120 is mixed with the soil, cement slurry is injected into the second reinforcement area 110 for mixing. The cement slurry concentration in the third reinforcement area 120 is greater than the cement concentration in the second reinforcement area 110. After the mixing is completed, the second reinforcement area 110 and the third reinforcement area 120 are stratified.

[0079] In this embodiment, the third reinforcement area 120 is located at the bottom and the second reinforcement area 110 is located at the top. During the layered reinforcement of the mixing pile, the third reinforcement area 120 is reinforced first and made stronger, providing a solid foundation for the second reinforcement area 110. Reinforcing the lower layer first and then the upper layer helps to better control quality during construction. The improved strength of the lower structure can more effectively support and distribute the load of the upper structure, thereby optimizing the overall construction effect.

[0080] In this embodiment, in steps S1 and S2, the overlap between the piles is 0.3 meters.

[0081] Through this embodiment, the 0.3-meter overlap between the mixing piles and the high-pressure rotary jet piles can ensure an effective connection between the two types of piles, thereby forming an integral reinforcement structure and improving the bearing capacity and stability of the foundation;

[0082] During construction, gaps may form between the two types of piles. A 0.3m overlap can fill these gaps and prevent uneven settlement or damage to the foundation caused by the gaps.

[0083] Example 3

[0084] This embodiment provides a shield parameter adjustment method for adjusting the drilling parameters of a shield machine. The steps are as follows:

[0085] S1. Division of trial excavation section

[0086] Starting from the starting end of the shield machine, 0-9 meters is divided into the first stage of trial excavation, 9-20 meters is divided into the second stage of trial excavation, 20-30 meters is divided into the third stage of trial excavation, and 30-50 meters is divided into the fourth stage of trial excavation.

[0087] S2. Adjustment of parameters for the first stage of trial excavation

[0088] During shield machine excavation, since the first stage is the reinforcement area, the shield machine's posture is controlled to keep the horizontal deviation between +20 and -20 mm, the horizontal trend between 0 and 1 mm, the vertical deviation between +20 and -20 mm, and the vertical trend between -5 and 5 mm. In the shield machine excavation parameters, the total thrust of the jack is set to less than 8000 kN, and the support point of the jack is set at the shield support device, which provides the jack with the driving force. Then, the cutterhead torque is set to less than 2000 kN.m, the cutterhead speed is maintained between 0.8 and 1.0 rpm, the excavation speed is controlled at less than 10 mm / min, and the soil bin pressure is maintained between 0 and 1.0 bar.

[0089] S3. Adjustment of parameters for the second stage of trial excavation

[0090] After the first phase of trial excavation, the shield passed through the reinforced area and entered the soil smoothly, and earth pressure balance was basically established. After the shield machine entered the soil, the total thrust of the jacks was adjusted to maintain at 10,000 kN. At this time, the shield machine excavation speed was increased to maintain at 20-30 mm / min. The horizontal deviation of the shield machine was adjusted to -30-+30 mm, and the horizontal trend was controlled at 0-1 mm. The vertical deviation was controlled between -30-+20 mm, and the vertical trend was controlled between -5-5 mm. The cutterhead torque was controlled at less than 2500 kN.m, the cutterhead speed was controlled at 1.0-1.2 rpm, and the soil bin pressure was controlled at 1.0-1.5 bar. After the shield passed through the reinforced area, grouting was carried out in the soil layer around the shield, with the grouting pressure controlled at 0.25 MPa and the grouting volume controlled at 4 m³.

[0091] S4. Adjustment of parameters for the third stage of trial excavation

[0092] Based on the excavation parameters of the second phase, the excavation parameters of the third phase were further adjusted. The shield thrust was set at 11,000 kN. The cutterhead speed was increased to 1.2-1.3 rpm, the shield excavation speed was increased to 30-40 mm / min, and the soil bin pressure was controlled at 1.3-1.6 bar. The shield machine's horizontal deviation, horizontal trend, vertical deviation, vertical trend, grouting pressure, and grouting volume remained the same as those of the second phase.

[0093] S5. Adjustment of parameters for the fourth stage of trial excavation

[0094] The horizontal deviation of the shield machine is controlled between -50 and +50 mm, the vertical deviation is controlled between -50 and +50 mm, the total thrust of the jack is controlled at 13,000 KN, the cutterhead torque is controlled at 3,000 KN.m, the cutterhead speed is controlled at 1.0 to 1.2, the excavation speed is controlled at 30 to 50 mm / min, and the other parameters are the same as those in the third stage.

[0095] Through this embodiment, the trial excavation can comprehensively test the overall performance of the shield machine, such as propulsion force, torque, etc., to ensure that it meets the construction requirements; by dividing the trial excavation section into the first trial excavation stage, the second trial excavation stage, the third trial excavation stage and the fourth trial excavation stage, the excavation parameters of the shield machine in different stages are gradually adjusted and optimized, thereby ensuring the construction safety and quality of subsequent excavation.

[0096] During the shield machine's initial reinforcement section, the total thrust of the jack is set to less than 8,000 kN, the cutterhead torque is set to less than 2,000 kN.m, the cutterhead speed is maintained between 0.8 and 1.0 rpm, the excavation speed is controlled at less than 10 mm / min, and the soil bin pressure is maintained between 0 and 1.0 bar. The low-thrust mode ensures high construction safety, especially in complex geological environments or where there are uncertainties. Lower thrust helps reduce potential risks.

[0097] After the shield machine successfully passes through the reinforced area and enters the soil, although increasing the thrust can increase the excavation speed, excessive thrust may lead to enhanced interaction between the shield machine and the surrounding soil, thereby increasing construction risks; therefore, the total thrust of the jack is maintained at 10,000KN, which not only ensures excavation efficiency but also avoids potential risks caused by excessive thrust.

[0098] The excavation parameters of the third and fourth stages are further increased until the shield machine passes through the trial excavation section, thereby obtaining reasonable parameters for the shield machine to drill in subsequent strata.

[0099] In this embodiment, when the shield machine enters the reinforcement area of ​​the first stage, the cutter head torque increases and foam is injected in front of the excavation chamber.

[0100] Through this embodiment, long-term excavation will cause tool wear and reduced cutting efficiency, which in turn increases the cutter head torque. By injecting foam to lubricate the surface of soil particles, the soil flow plasticity is improved, and the cutter head torque is reduced. The foam can effectively prevent the debris from sticking to the cutter head, reduce the formation of mud cakes, keep the cutter head clean, and improve work efficiency.

[0101] In this embodiment, during the tunneling process of the shield machine, the segments are lined behind the shield machine. The segments shall not have internal or external penetrating cracks, and shall not have cracks with a width greater than 0.2 mm and concrete spalling during the service stage.

[0102] Through this embodiment, cracks and spalling can easily reduce the bearing capacity of the pipe segments and increase the risk of tunnel collapse; cracks and spalling can destroy the waterproof layer of the pipe segments, causing water leakage in the tunnel, affecting the normal use and durability of the tunnel.

[0103] In this embodiment, during the starting process of the shield machine, grease needs to be injected into the shield tail at the position of the wire brush.

[0104] Through this embodiment, injecting grease into the shield tail can form a pressure-sealed chamber, effectively preventing the infiltration of groundwater, mud, etc., and improving the safety of the excavation process.

[0105] In this embodiment, during the shield machine excavation process, synchronous grouting and secondary grouting control are required to be implemented. Synchronous grouting is carried out simultaneously with shield excavation. A grouting machine and a grouting pipe are used to pass through the pipe segment and grout the soil layer outside the pipe segment; the secondary grouting control performs two or more backfill grouting according to the actual project conditions, such as pipe segment leakage, tunnel settlement, etc.

[0106] Through this embodiment, synchronous grouting can ensure the early and late stability of the segment lining by injecting slurry evenly and densely; secondary or multiple backfill grouting can make up for the part not filled by the first grouting and fill the gap caused by slurry shrinkage; prevent the expansion of the surrounding stratum relaxation range and enhance the stability of the stratum.

[0107] In this embodiment, elastic sealing gaskets are added at the interfaces between the pipe segments. The dimensional accuracy of the elastic sealing gaskets is as follows: height tolerance +0.5mm; maximum width tolerance ±1.0mm; top surface width tolerance ±1.0mm; foot width tolerance ±1.0mm; and aperture tolerance ±0.2mm.

[0108] Through this embodiment, the elastic sealing gasket can effectively fill the gaps between the pipe segments, prevent the infiltration of impurities such as soil and water, and ensure the overall sealing of the tunnel.

[0109] like Figure 2-6As shown, this embodiment provides a shield support device, which is used in S2~S5 of a shield parameter adjustment method, including a device body 200, and the device body 200 includes a first support rod 240 arranged along the length direction of the shield machine starting shaft and located on both sides of the shield machine track; a reaction frame 210 perpendicular to the first support rod 240 is provided at one end of the first support rod 240, and the reaction frame 210 includes two vertical rods 220 perpendicular to the first support rod 240, and the upper and lower ends of the two vertical rods 220 are provided with a connecting rod 310 for connecting the two vertical rods 220; the end of the first support rod 240 close to the reaction frame 210 is provided with a second support rod 270 arranged obliquely, and the end of the second support rod 270 away from the first support rod 240 is provided with a third support rod 290 arranged parallel to the first support rod 240; a first oblique support rod 280 arranged obliquely is provided between the second support rod 270 and the vertical rod 220, and a second oblique support rod 201 is provided between the third support rod 290 and the vertical rod 220.

[0110] According to this embodiment, the device body 200 is set in the starting shaft and is located behind the shield machine. The starting shaft of the shield machine is connected to the previous tunnel. The shield machine needs to use the rear jack to provide thrust during the starting process. Before the shield machine starts, a track is first laid at the bottom of the starting shaft, and then two first support rods 240, a second support rod 270 and a third support rod 290 are set on both sides of the track along the length direction of the starting shaft. Then, the reaction frame 210 is welded or fixed vertically on the two first support rods 240 by bolts, and then the first diagonal support rod 280 is fixed. 0 is installed between the vertical pole 220 and the second support rod 270, so that the two ends of the first oblique support rod 280 are welded to the vertical pole 220 and the second support rod 270; the second support rod 270 is tilted to increase the supporting force of the second support rod 270, thereby preferably improving the supporting strength of the reaction frame 210; after the first oblique support rod 280 is connected, the two ends of the second oblique support rod 201 are respectively welded to the vertical pole 220 and the third support rod 290, and the reaction frame 210 is supported by the second oblique support rod 201, thereby further strengthening the overall supporting strength of the reaction frame 210.

[0111] In this embodiment, a third diagonal support rod 320 is provided between the connecting rod 310 and the vertical rod 220. A support ring 230 fixedly connected to the connecting rod 310, the vertical rod 220 and the third diagonal support rod 320 is provided at one end face of the reaction frame 210 away from the second diagonal support rod 201.

[0112] Through this embodiment, the jack at the rear of the shield machine rests on the support ring 230, the support ring 230 presses on the reaction frame 210, and the third diagonal support rod 320 is located between the connecting rod 310 and the vertical rod 220, thereby better improving the overall structural strength of the reaction frame 210; at the same time, the support ring 230 rests on the connecting rod 310, the vertical rod 220 and the third diagonal support rod 320, thereby increasing the contact area between the support ring 230 and the reaction frame 210, preventing the reaction frame 210 from being deformed due to uneven force when the support ring 230 rests on the reaction frame 210 when the jack applies pressure.

[0113] In this embodiment, a support plate 260 for connecting the two first support rods 240 is provided at the connection between the second support rod 270 and the first support rod 240; a connecting rod 310 located at the lower end of the vertical rod 220 is provided with a plurality of first support blocks 250 arranged at intervals along the length direction of the connecting rod 310 and extending toward the support plate 260; a connecting rod 310 located at the upper end of the vertical rod 220 is provided with a plurality of second support blocks 202 arranged at intervals along the length direction of the connecting rod 310.

[0114] Through this embodiment, the first support block 250 rests on the support plate 260, and the second support block 202 rests on the top of the tunnel connected to the starting well. Through the joint support of the first support block 250, the support plate 260 and the second support block 202, the overall structural strength and support strength of the device body 200 are further strengthened.

[0115] Through the joint action of the second diagonal support rod 201, the first diagonal support rod 280, the second support rod 270, the first support block 250 and the second support block 202, the overall structural strength and support strength of the device main body 200 are better improved; it is prevented that during the trial excavation section of the shield machine, the total thrust of the jack needs to be gradually increased during the trial excavation section of the shield machine, resulting in insufficient structural strength of the device main body 200, damage to the device main body 200, and inability to carry out construction, affecting the construction progress.

[0116] Example 4

[0117] like Figure 7-8 As shown, this embodiment provides a shield machine anti-rotation tooling, which is suitable for use when drilling at the starting end of the shield machine, including a tooling body 420, and the tooling body 420 includes two limit plates 420 arranged at the bottom of the shield machine; the limit plates 420 and the shield machine base 430 together constitute a limit interval 450 for limiting the rotation of the shield machine body 410.

[0118] Through this embodiment, when laying the shield machine track, it is necessary to lay the base 430 at the bottom of the shield track, and then lay the slide rail 440 on the base 430. After the slide rail 440 is laid, the front shield, middle shield and rear shield of the shield machine are respectively hoisted onto the slide rail 440 for assembly. After the assembly is completed, the installer welds the limit plates 420 to the side walls of the front shield and the middle shield of the shield machine, and makes the limit plates 420 close to the base 430. The end face of the limit plate 420 close to the base 430 rests on the base 430, so that when the shield machine is excavating, the torque of the cutter head cutting into the soil is large, driving the shield machine itself to rotate, and the rotation of the shield machine itself is blocked by the limit plates 420, thereby preventing the shield machine from derailing and causing damage.

[0119] In this embodiment, the limiting plate 420 includes a connecting block 510 welded to the shield machine body 410 .

[0120] According to this embodiment, the installer completes the connection between the connection block 510 and the shield machine by welding the connection block 510 to the shield machine.

[0121] In this embodiment, an arc-shaped welding plate 520 is provided at one end of the connecting block 510 close to the shield machine body 410 ; the width of the welding plate 520 is greater than the width of the connecting block 510 .

[0122] Through this embodiment, since the side wall of the shield machine is curved, the arc-shaped welding plate 520 can better fit the side wall of the shield machine. At the same time, the width of the welding plate 520 is greater than the width of the connecting block 510, thereby increasing the welding area between the connecting block 510 and the shield machine, and improving the connection strength between the welding plate 520 and the shield machine.

[0123] In this embodiment, the connecting block 510 and the welding plate 520 are both made of stainless steel.

[0124] Through this embodiment, the stainless steel has a high hardness and structural strength, which prevents the connecting block 510 and the welding plate 520 from being squeezed by the base 430 and causing damage and deformation when the shield machine rotates.

[0125] In this embodiment, the connecting block 510 has a length of 200 mm, a width of 100 mm, and a height of 20 mm.

[0126] Through this embodiment, the connecting block 510 has a smaller volume, thus avoiding material waste.

[0127] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application based on one or several embodiments provided in the present application to obtain other embodiments, and these embodiments do not exceed the scope of protection of the present application.

[0128] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The embodiments shown in the embodiments are only part of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by the above and, without departing from the purpose of the present invention, designs a structure and embodiment similar to the technical solution without creatively designing, they shall fall within the scope of protection of the present invention.

Claims

1. A shield parameter adjustment method, the steps are as follows: S1. Division of trial excavation section Starting from the starting end of the shield machine, 0-9 meters is divided into the first stage of trial excavation, 9-20 meters is divided into the second stage of trial excavation, 20-30 meters is divided into the third stage of trial excavation, and 30-50 meters is divided into the fourth stage of trial excavation; S2. Adjustment of parameters for the first stage of trial excavation During shield machine excavation, since the first stage is the reinforcement area, the shield machine's posture is controlled to keep the horizontal deviation between +20 and -20 mm, the horizontal trend between 0 and 1 mm, the vertical deviation between +20 and -20 mm, and the vertical trend between -5 and 5 mm. In the shield machine excavation parameters, the total thrust of the jack is set to less than 8000 kN, and the support point of the jack is set at the shield support device, which provides the jack with the driving force. Then, the cutterhead torque is set to less than 2000 kN.m, the cutterhead speed is maintained between 0.8 and 1.0 rpm, the excavation speed is controlled at less than 10 mm / min, and the soil bin pressure is maintained between 0 and 1.0 bar. S3. Adjustment of parameters for the second stage of trial excavation After the first phase of trial excavation, the shield passed through the reinforced area and entered the soil smoothly, and earth pressure balance was basically established. After the shield machine entered the soil, the total thrust of the jacks was adjusted to maintain at 10,000 kN. At this time, the shield machine excavation speed was increased to maintain at 20-30 mm / min. The horizontal deviation of the shield machine was adjusted to -30-+30 mm, and the horizontal trend was controlled at 0-1 mm. The vertical deviation was controlled between -30-+20 mm, and the vertical trend was controlled between -5-5 mm. The cutterhead torque was controlled at less than 2500 kN.m, the cutterhead speed was controlled at 1.0-1.2 rpm, and the soil bin pressure was controlled at 1.0-1.5 bar. After the shield passed through the reinforced area, grouting was carried out in the soil layer around the shield, with the grouting pressure controlled at 0.25 MPa and the grouting volume controlled at 4 m³. S4. Adjustment of parameters for the third stage of trial excavation Based on the excavation parameters of the second phase, the excavation parameters of the third phase were further adjusted. The shield thrust was set at 11,000 kN. The cutterhead speed was increased to 1.2-1.3 rpm, the shield excavation speed was increased to 30-40 mm / min, and the soil bin pressure was controlled at 1.3-1.6 bar. The shield machine's horizontal deviation, horizontal trend, vertical deviation, vertical trend, grouting pressure, and grouting volume remained the same as those of the second phase. S5. Adjustment of parameters for the fourth stage of trial excavation The horizontal deviation of the shield machine was controlled between -50 and +50 mm, the vertical deviation was controlled between -50 and +50 mm, the total thrust of the jack was controlled at 13,000 KN, the cutterhead torque was controlled at 3,000 KN.m, the cutterhead speed was controlled at 1.0 to 1.2 rpm, the excavation speed was controlled at 30 to 50 mm / min, and the other parameters were the same as those in the third stage.

2. A shield parameter adjustment method according to claim 1, characterized in that: In step S2, when the shield machine enters the first stage reinforcement area, the cutter head torque increases and foam is injected in front of the excavation chamber.

3. A shield parameter adjustment method according to claim 1, characterized in that: During the tunneling process of the shield machine, the segments are lined behind the shield machine. There shall be no internal or external penetrating cracks in the segments, and no cracks with a width greater than 0.2mm and no concrete spalling during the use phase.

4. A shield parameter adjustment method according to claim 1, characterized in that: In step S2, during the initial operation of the shield machine, grease needs to be injected into the shield tail at the wire brush position.

5. A shield parameter adjustment method according to claim 1, characterized in that: During the shield machine excavation process, synchronous grouting and secondary grouting control are required. Synchronous grouting is carried out simultaneously with shield excavation. A grouting machine and a grouting pipe are used to pass through the pipe segment and grout the soil layer outside the pipe segment. Secondary grouting control is carried out two or more times of backfill grouting according to the actual situation of the project.

6. A shield parameter adjustment method according to claim 1, characterized in that: Elastic sealing gaskets are added at the interfaces between the segments. The dimensional accuracy of the elastic sealing gaskets is: height tolerance +0.5mm; maximum width tolerance is ±1.0mm; top surface width tolerance is ±1.0mm; foot width tolerance is ±1.0mm; aperture tolerance is ±0.2mm.

7. A shield support device for implementing a shield parameter adjustment method according to claim 1, characterized in that: The invention comprises a device body (200), wherein the device body (200) comprises a first support rod (240) arranged along the length direction of the shield machine starting shaft and located on both sides of the shield machine track; a reaction frame (210) perpendicular to the first support rod (240) is provided at one end of the first support rod (240); the reaction frame (210) comprises two vertical rods (220) perpendicular to the first support rod (240); and the two vertical rods (220) are provided with a connecting rod (31) at both the upper and lower ends for connecting the two vertical rods (220). 0); an end of the first support rod (240) close to the reaction frame (210) is provided with a second support rod (270) arranged obliquely, and an end of the second support rod (270) away from the first support rod (240) is provided with a third support rod (290) arranged parallel to the first support rod (240); a first oblique support rod (280) is provided obliquely between the second support rod (270) and the vertical rod (220), and a second oblique support rod (201) is provided between the third support rod (290) and the vertical rod (220).

8. A shield support device according to claim 7, characterized in that: A third diagonal support rod (320) is provided between the connecting rod (310) and the vertical rod (220). A support ring (230) fixedly connected to the connecting rod (310), the vertical rod (220) and the third diagonal support rod (320) is provided at an end surface of the reaction frame (210) away from the second diagonal support rod (201).

9. The shield support device according to claim 7, characterized in that: A support plate (260) for connecting the two first support rods (240) is provided at the connection point between the second support rod (270) and the first support rod (240); a plurality of first support blocks (250) are provided at the connecting rod (310) at the lower end of the vertical rod (220), which are spaced apart along the length direction of the connecting rod (310) and extend toward the support plate (260); and a plurality of second support blocks (202) are provided at the connecting rod (310) at the upper end of the vertical rod (220), which are spaced apart along the length direction of the connecting rod (310).

10. A shield tunneling starting end drilling method, comprising the following steps: S1, reinforcement of the origin; S2. Shield machine drilling parameter adjustment is achieved by a shield parameter adjustment method described in any one of claims 1-6, and shield parameter adjustment is achieved by a shield support device described in any one of claims 7-9.

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