阅读说明：本技术 一种盾构长距离空推过矿山法隧道施工方法 (Construction method for shield long-distance air-pushing mine-crossing tunnel ) 是由 余南山 贾瑞华 鲁文博 李毅 朱海涛 周浩 刘康宇 李子硕 于 2020-10-27 设计创作，主要内容包括：本发明公开了一种盾构长距离空推过矿山法隧道施工方法,包括喷射混凝土封闭掌子面、暗挖隧道轮廓线测量并复核隧道轴线偏差、暗挖隧道水泥砂浆回填、根据盾构出渣含水量在空推前施作止水环、在距离矿山法掌子面10m范围内适当调整盾构掘进参数、盾构空推与底部同步注浆、增加盾构姿态监控次数和管片脱出盾尾以后二次注浆。本发明克服了传统盾构空推的不足之处,确保空推段管片不需更多的型钢加固,同时保证止水胶条挤压密贴,整体防水质量好,盾构接收姿态稳定可控。(The invention discloses a shield long-distance air-pushing mine-method tunnel construction method which comprises the steps of spraying concrete to close a tunnel face, measuring an underground excavation tunnel contour line, rechecking the axis deviation of a tunnel, backfilling underground excavation tunnel cement mortar, constructing a water stop ring before air-pushing according to the slag water content of a shield, properly adjusting shield tunneling parameters within a range of 10m from the tunnel face of the mine method, synchronously grouting the shield air-pushing and the bottom, increasing the shield posture monitoring times and performing secondary grouting after a duct piece is separated from a shield tail. The invention overcomes the defects of the traditional shield empty pushing, ensures that the pipe sheet at the empty pushing section does not need to be reinforced by more section steel, ensures that the water-stopping adhesive tape is extruded and closely attached, has good integral waterproof quality and stable and controllable shield receiving attitude.)

1. A shield long-distance air-propelled mine-through tunnel construction method comprises the steps of tunnel face sealing, undercut tunnel contour line measurement, tunnel cement mortar backfilling, water stop ring construction, shield tunneling soil bin pressure control, bottom synchronous grouting and secondary grouting, and is characterized by comprising the following construction steps:

s1: after the tunnel is dug in the dark, spraying concrete with the thickness of 100mm on the tunnel face to seal the tunnel face;

s2: measuring the tunnel contour line before backfilling the underground excavated tunnel, and checking the axis error of the underground excavated tunnel;

s3: cement mortar is backfilled in the underground excavated tunnel, the height of the backfilled cement mortar is determined by calculating the counterforce required by shield propulsion, three layers are vertically divided in the backfilling process for ensuring the backfilling to be compact, and the backfilling is sequentially carried out in a longitudinal segmentation mode according to the backfilling length;

s4: when the shield is tunneled to the position of 5-10 rings in front of the boundary of the tunnel, water-stopping ring construction is carried out in the length range from the tail of the shield to the first trolley;

s5: adjusting the shield tunneling parameters within 10m from the tunnel face of the mine method to ensure the stable shield posture when the air thrust is started;

s6: the bottom is synchronously grouted in the tunneling process, so that the bottom of the duct piece is ensured to be densely filled, and the duct piece is prevented from sinking and staggering;

s7: in the air pushing process, the muck in the soil bin is released according to the ground settlement monitoring condition, and the shield attitude is stabilized to be pushed;

s8: the number of times of monitoring the posture of the shield machine is increased in the propelling process of the shield machine, so that the stability of the tunneling posture of the shield machine is ensured;

s9: after the duct piece is separated from the shield tail, secondary grouting is performed through the top of the duct piece and hoisting holes on two sides of the duct piece as grouting holes, so that grouting and filling on the back of the duct piece are compact, and stable forming posture of the duct piece is guaranteed.

2. The method of claim 1, wherein the backfill height is determined to be above 2/3 tunnel diameter by calculating the reaction force required for shield propulsion before backfill in step S2.

3. The method for constructing the shield long-distance empty-pushing mine-method tunnel according to claim 1, wherein in the step S5, within a range of 10m from the working face of the mine method, the shield equipment should reduce the active thrust, the propelling speed and the cutter head rotating speed, so as to ensure the stable posture of the shield during the empty pushing.

4. The method for constructing a tunnel by a shield long-distance air-pushing mine method according to claim 1, wherein the synchronous grouting in the step S6 is used for ensuring the bottom of the tunnel to be tightly filled, and the grouting liquid is cement mortar.

5. The method for constructing the tunnel by the shield long-distance air-pushing mine method according to claim 1, wherein the secondary grouting in the step S9 is performed on the top and two sides of the tunnel segment to ensure that the gap is tightly filled, and the grouting liquid is cement mortar and water glass.

Technical Field

The invention relates to the technical field of tunnel construction, in particular to a tunnel construction method by a shield long-distance air-pushing mine method.

Background

As the shield is widely applied to tunnel construction, the encountered construction conditions are not uniform, and the shield safely passes through the tunnel in the underground excavation method interval, so that the supporting structure meets the design specification requirement and has higher requirement on the construction method; under the special construction condition, the traditional shield air-pushing underground excavation method tunnel is usually backfilled by pea gravel, but the backfilling operation is inconvenient, the strength is general after backfilling, gaps are easy to exist between the assembled duct pieces and the underground excavation tunnel lining to form a through channel for the pea gravel, underground water behind the shield is easy to flow into the tunnel face, and safety risks are generated; in the shield empty pushing process, due to the fact that the strength of backfill materials, support linings and surrounding rock strata of the underground excavated tunnel is different, the requirement on control of shield tunneling parameters is high, meanwhile, due to the limitation of the contour line of the underground excavated tunnel, the requirement on the propelling posture of the shield is also high, due to the fact that a gap exists between the primary support of the underground excavated tunnel and the segments of the shield, the settlement deformation of the segments is determined by the grouting and filling quality, and staggered platforms are easily formed after the segments are assembled; the shield axis and the construction quality are difficult to control due to a plurality of influencing factors.

Disclosure of Invention

The invention provides a tunnel construction method for a shield long-distance air-pushing mine method, aiming at overcoming the technical defects that the shield tunneling parameter control and the propelling attitude are higher in the traditional shield air-pushing process in the prior art, so that the shield axis and the construction quality are difficult to control.

The invention realizes the aim through the following technical scheme, and the shield long-distance air-pushing mine method tunnel construction method comprises the steps of tunnel face sealing, undercut tunnel contour line measurement, tunnel cement mortar backfilling, water stop ring construction, shield tunneling soil bin pressure control, bottom synchronous grouting and secondary grouting, and is characterized in that the construction method comprises the following construction steps:

s1: after the tunnel is dug in the dark, spraying concrete with the thickness of 100mm on the tunnel face to seal the tunnel face;

s2: measuring the tunnel contour line before backfilling the underground excavated tunnel, and checking the axis error of the underground excavated tunnel;

s3: cement mortar is backfilled in the underground excavated tunnel, the height of the backfilled cement mortar is determined by calculating the counterforce required by shield propulsion, three layers are vertically divided in the backfilling process for ensuring the backfilling to be compact, and the backfilling is sequentially carried out in a longitudinal segmentation mode according to the backfilling length;

s4: when the shield is tunneled to the position of 5-10 rings in front of the boundary of the tunnel, water-stopping ring construction is carried out in the length range from the tail of the shield to the first trolley;

s5: adjusting the shield tunneling parameters within 10m from the tunnel face of the mine method to ensure the stable shield posture when the air thrust is started;

s6: the bottom is synchronously grouted in the tunneling process, so that the bottom of the duct piece is ensured to be densely filled, and the duct piece is prevented from sinking and staggering;

s7: in the air pushing process, the muck in the soil bin is released according to the ground settlement monitoring condition, and the shield attitude is stabilized to be pushed;

s8: the number of times of monitoring the posture of the shield machine is increased in the propelling process of the shield machine, so that the stability of the tunneling posture of the shield machine is ensured;

s9: after the duct piece is separated from the shield tail, secondary grouting is performed through the top of the duct piece and hoisting holes on two sides of the duct piece as grouting holes, so that grouting and filling on the back of the duct piece are compact, and stable forming posture of the duct piece is guaranteed.

In the construction method of the shield long-distance air-pushing mine-method tunnel, before backfilling, the backfill height is determined to be higher than the 2/3 tunnel diameter through calculation of the reaction force required by shield pushing in step S2.

In the construction method for the shield long-distance air-pushing mine-method tunnel, in the step S5, the shield equipment should reduce the driving thrust, slow the propelling speed and slow the cutter head rotating speed within a range of 10m from the working face of the mine method, so as to ensure the stable posture of the shield during air-pushing.

In the construction method of the shield long-distance air-pushing mine-method tunnel, the synchronous grouting in the step S6 is used for ensuring the bottom of the tunnel to be tightly filled, and the grouting liquid is cement mortar.

In the construction method of the shield long-distance air-pushing mine-method tunnel, the secondary grouting in the step S9 is performed on the top and two sides of the tunnel segment, so that the gap is guaranteed to be densely filled, and the grouting liquid is cement mortar and water glass.

Generally, compared with the prior art, the technical scheme of the invention can achieve the following beneficial effects: the construction method of the shield long-distance air-pushing mine-method tunnel can realize the long-distance air-pushing of the shield through the mine-method tunnel, and has the advantages of safe and reliable construction, convenient operation, good quality and the like.

Drawings

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings, in which:

fig. 1 is a construction flow chart of a shield long-distance air-pushing mine method tunnel construction method of the invention.

Detailed Description

As shown in fig. 1, a construction flow chart of the construction method of the shield long-distance air-pushing mine-method tunnel of the invention comprises the steps of underground excavation tunnel cement mortar backfilling, water-stop ring construction, shield tunneling soil bin pressure control, bottom synchronous grouting and secondary grouting, and the construction process comprises the following steps:

the method comprises the following steps: after the construction of the underground tunnel is completed, spraying concrete with the thickness of 100mm on the tunnel face, and sealing the tunnel face to ensure the stability of the tunnel face before the tunnel is backfilled and ensure the safety and reliability of the later tunnel measurement and backfilling work;

step two: checking the axis of the undercut tunnel and the designed axis by measuring the contour line of the tunnel, and optimizing shield driving parameters when the shield drives the undercut tunnel at the later stage to ensure that the shield driving axis is correct;

step three: cement mortar is backfilled in the underground excavated tunnel, and the counterforce required to be provided by the shield cutter head is calculated through the thrust required by splicing shield segments, so that the backfill height of the tunnel is obtained, the total amount of backfilled cement mortar is ensured to be economic and reasonable, and the shield propulsion requirement is met;

step four: when the shield is tunneled to the position of 5-10 rings in front of the boundary of the tunnel, water stop ring construction is carried out in the length range from the tail of the shield to the first trolley, so that underground water behind the cutter can be prevented from flowing into the tunnel by the underground excavation method through the crack channel, and the construction safety is ensured;

step five: when the shield tunnels a tunnel in a subsurface excavation section, cement mortar fills a gap between a primary support of a mine method and a duct piece, and double-liquid slurry (cement slurry and water glass) is injected into a hoisting hole at the bottom of the duct piece after the duct piece is separated from a shield tail, so that the duct piece is prevented from sinking and staggering;

step six: the muck in the soil bin is released according to the ground settlement monitoring condition, the shield attitude propulsion is stabilized, and the control accuracy of a shield propulsion axis is ensured;

step seven: due to the fact that geological conditions on two sides of the working face of the mine method are changed, shield tunneling parameters need to be adjusted properly, the shield equipment properly reduces driving thrust, slows down the propelling speed and slows down the rotating speed of a cutter head within a range of 10m from the working face of the mine method, meanwhile, the number of times of monitoring the posture of the shield machine is increased, and the stable tunneling posture of the shield machine is guaranteed;

step eight: because of synchronous slip casting only has carried out the slip casting to the segment bottom, the slip casting effect is difficult to be guaranteed, need in time carry out the quadratic compensation thick liquid to the segment, ensures that segment back slip casting is filled closely knit, guarantees that the shaping gesture of segment is stable.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.