Currently,the water inrush hazards during tunnel construction,the water leakage during tunnel operation,and the accompanying disturbances to the ecological environment have become the main problems that affect the str...Currently,the water inrush hazards during tunnel construction,the water leakage during tunnel operation,and the accompanying disturbances to the ecological environment have become the main problems that affect the structural safety of tunnels in water-rich regions.In this paper,a tunnel seepage model testing system was used to conduct experiments of the grouting circle and primary support with different permeability coefficients.The influences of the supporting structures on the water inflow laws and the distribution of the water pressure in the tunnel were analyzed.With the decrease in the permeability coefficient of the grouting circle or the primary support,the inflow rate of water into the tunnel showed a non-linear decreasing trend.In comparison,the water inflow reduction effect of grouting circle was much better than that of primary support.With the increase of the permeability coefficient of the grouting ring,the water pressure behind the primary lining increases gradually,while the water pressure behind the grouting ring decreases.Thus,the grouting of surrounding rock during the construction of water-rich tunnel can effectively weaken the hydraulic connection,reduce the influence range of seepage,and significantly reduce the decline of groundwater.Meanwhile,the seepage tests at different hydrostatic heads and hydrodynamic heads during tunnel operation period were also conducted.As the hydrostatic head decreased,the water pressure at each characteristic point decreased approximately linearly,and the water inflow rate also had a gradual downward trend.Under the action of hydrodynamic head,the water pressure had an obvious lagging effect,which was not conducive to the stability of the supporting structures,and it could be mitigated by actively regulating the drainage rate.Compared with the hydrostatic head,the hydrodynamic head could change the real-time rate of water inflow to the tunnel and broke the dynamic balance between the water pressure and water inflow rate,thereby affecting the stress state on the supporting structures.展开更多
呼吉尔特矿区属于鄂尔多斯盆地侏罗系煤田深埋区,可采煤层上覆较强富水性厚层砂岩含水层。随着煤层开采,顶板水进入矿井,严重影响矿井安全生产。矿区范围内,各生产矿井涌水量均较大,最大矿井涌水量达到2289 m 3/h,且仍呈上升趋势。针对...呼吉尔特矿区属于鄂尔多斯盆地侏罗系煤田深埋区,可采煤层上覆较强富水性厚层砂岩含水层。随着煤层开采,顶板水进入矿井,严重影响矿井安全生产。矿区范围内,各生产矿井涌水量均较大,最大矿井涌水量达到2289 m 3/h,且仍呈上升趋势。针对这一情况,以该矿区涌水量最大的某矿井为例,对该矿区矿井涌水量变化规律和影响因素,从开采煤层上覆含水层赋存特征、巷道掘进长度、采空区半径、含水层疏降等方面,做了分析研究。结果表明:该矿区煤层顶板导水裂缝带范围内,发育有2~3层砂岩含水层,富水性差异较大,不同程度地影响矿井涌水量。在建井阶段,矿井涌水量随着巷道进尺的增加而增大,而矿井单位进尺涌水量和巷道单位进尺涌水量呈减小趋势。采前对工作面上覆含水层静储量进行计算,采取超前预疏放措施,充分疏放含水层静储量,可达到安全回采条件。矿井生产建设过程中,矿井涌水量先期呈大幅度增大的趋势,随着矿井采空区面积的不断增大,疏放影响范围增大,矿井涌水量增长幅度趋缓。展开更多
基金supported by the Chongqing Natural Science Foundation(No.cstc2020jcyjmsxm X0904)the Chongqing Talent Plan(No.CQYC2020058263)+3 种基金the Chongqing Technology Innovation and Application Development Project(No.cstc2021ycjh-bgzxm0246)the China Postdoctoral Science Foundation(No.2021M693739)the Sichuan Science and Technology Program(No.2021YJ0539)the Natural Science foundation of Jiangsu higher education institutions of China(Grant No.19KJD170001)。
文摘Currently,the water inrush hazards during tunnel construction,the water leakage during tunnel operation,and the accompanying disturbances to the ecological environment have become the main problems that affect the structural safety of tunnels in water-rich regions.In this paper,a tunnel seepage model testing system was used to conduct experiments of the grouting circle and primary support with different permeability coefficients.The influences of the supporting structures on the water inflow laws and the distribution of the water pressure in the tunnel were analyzed.With the decrease in the permeability coefficient of the grouting circle or the primary support,the inflow rate of water into the tunnel showed a non-linear decreasing trend.In comparison,the water inflow reduction effect of grouting circle was much better than that of primary support.With the increase of the permeability coefficient of the grouting ring,the water pressure behind the primary lining increases gradually,while the water pressure behind the grouting ring decreases.Thus,the grouting of surrounding rock during the construction of water-rich tunnel can effectively weaken the hydraulic connection,reduce the influence range of seepage,and significantly reduce the decline of groundwater.Meanwhile,the seepage tests at different hydrostatic heads and hydrodynamic heads during tunnel operation period were also conducted.As the hydrostatic head decreased,the water pressure at each characteristic point decreased approximately linearly,and the water inflow rate also had a gradual downward trend.Under the action of hydrodynamic head,the water pressure had an obvious lagging effect,which was not conducive to the stability of the supporting structures,and it could be mitigated by actively regulating the drainage rate.Compared with the hydrostatic head,the hydrodynamic head could change the real-time rate of water inflow to the tunnel and broke the dynamic balance between the water pressure and water inflow rate,thereby affecting the stress state on the supporting structures.
文摘呼吉尔特矿区属于鄂尔多斯盆地侏罗系煤田深埋区,可采煤层上覆较强富水性厚层砂岩含水层。随着煤层开采,顶板水进入矿井,严重影响矿井安全生产。矿区范围内,各生产矿井涌水量均较大,最大矿井涌水量达到2289 m 3/h,且仍呈上升趋势。针对这一情况,以该矿区涌水量最大的某矿井为例,对该矿区矿井涌水量变化规律和影响因素,从开采煤层上覆含水层赋存特征、巷道掘进长度、采空区半径、含水层疏降等方面,做了分析研究。结果表明:该矿区煤层顶板导水裂缝带范围内,发育有2~3层砂岩含水层,富水性差异较大,不同程度地影响矿井涌水量。在建井阶段,矿井涌水量随着巷道进尺的增加而增大,而矿井单位进尺涌水量和巷道单位进尺涌水量呈减小趋势。采前对工作面上覆含水层静储量进行计算,采取超前预疏放措施,充分疏放含水层静储量,可达到安全回采条件。矿井生产建设过程中,矿井涌水量先期呈大幅度增大的趋势,随着矿井采空区面积的不断增大,疏放影响范围增大,矿井涌水量增长幅度趋缓。
