Under barometric pressure, groundwater flow in well-aquifer systems is a kind of hydromechanical coupling problem. Applying the flux boundary conditions on borehole wall and water pressure equilibrium conditions insid...Under barometric pressure, groundwater flow in well-aquifer systems is a kind of hydromechanical coupling problem. Applying the flux boundary conditions on borehole wall and water pressure equilibrium conditions inside and outside the borehole wall under barometric pressure （BP）, an analytic solution to well-water level changes has been proposed in this paper. The formulation shows that the BP coefficients increase with time and tend to BP constant. The Change of BP coefficients over time depends only on the ratio of transmissivity （T） to the well radius squared （ r2, ） , and has nothing to do with the change in BP. The BP constant only relates to aquifer loading efficiency （B）, and has nothing to do with the aquifer transmissivity and well radius. The BP coefficients＇ change over time in the analytic formulation is consistent with the analysis of measured data from the Nanxi wells. Based on the BP coefficient changes over time, a parameter estimation method is suggested and discussed in its application to the estimation of the aquifer BP constant （or B） and transmissivity by using the Nanxi well data.展开更多
This case study describes the effects of a grouting process developed to decrease groundwater flow exiting from a ruptured mine ventilation shaft lining in Luling coal mine at Huaibei, China. The primary purpose of gr...This case study describes the effects of a grouting process developed to decrease groundwater flow exiting from a ruptured mine ventilation shaft lining in Luling coal mine at Huaibei, China. The primary purpose of grouting at this site is to prevent groundwater flow into the mine from adjacent aquifers. The study supports a transport perspective to describe the miscible grout movement, and provides an approximate analytical method to determine grout concentration based on Wilson and Miller＇s （1978） model. This study shows that the breakthrough curves （BTCs） established from the Wilson and Miller＇s model match the experimental BTCs obtained from test grouting performed at the site, and Rd a retardation factor of 1.1 is determined. The retardation factor and the BTC ave subsequently used to guide the actual production grouting. The monitored result shows that the groundwater inflow at the disrupted ventilation well has been reduced by 47% after drilling and grouting just one borehole. The discharge rate was measured at no more than 4 m^3/h after completion of four injection boreholes, which is about 13% of the 30 m^3/h before grouting.展开更多
基金supported by special funds for Public Welfare Scientific Research of Ministry of Science and Technology,PRC(200808055)Scientific Research Project of Education Department,Hebei Province(Z2009104),China
文摘Under barometric pressure, groundwater flow in well-aquifer systems is a kind of hydromechanical coupling problem. Applying the flux boundary conditions on borehole wall and water pressure equilibrium conditions inside and outside the borehole wall under barometric pressure （BP）, an analytic solution to well-water level changes has been proposed in this paper. The formulation shows that the BP coefficients increase with time and tend to BP constant. The Change of BP coefficients over time depends only on the ratio of transmissivity （T） to the well radius squared （ r2, ） , and has nothing to do with the change in BP. The BP constant only relates to aquifer loading efficiency （B）, and has nothing to do with the aquifer transmissivity and well radius. The BP coefficients＇ change over time in the analytic formulation is consistent with the analysis of measured data from the Nanxi wells. Based on the BP coefficient changes over time, a parameter estimation method is suggested and discussed in its application to the estimation of the aquifer BP constant （or B） and transmissivity by using the Nanxi well data.
基金the National Natural Science Foundation of China (No. 40672154)the New Century Excellent Talents in University (No. NCET-06-0541)
文摘This case study describes the effects of a grouting process developed to decrease groundwater flow exiting from a ruptured mine ventilation shaft lining in Luling coal mine at Huaibei, China. The primary purpose of grouting at this site is to prevent groundwater flow into the mine from adjacent aquifers. The study supports a transport perspective to describe the miscible grout movement, and provides an approximate analytical method to determine grout concentration based on Wilson and Miller＇s （1978） model. This study shows that the breakthrough curves （BTCs） established from the Wilson and Miller＇s model match the experimental BTCs obtained from test grouting performed at the site, and Rd a retardation factor of 1.1 is determined. The retardation factor and the BTC ave subsequently used to guide the actual production grouting. The monitored result shows that the groundwater inflow at the disrupted ventilation well has been reduced by 47% after drilling and grouting just one borehole. The discharge rate was measured at no more than 4 m^3/h after completion of four injection boreholes, which is about 13% of the 30 m^3/h before grouting.
