As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mini...As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.展开更多
Australia has developed extensive policies and guidelines for the management of its water. The City of Salisbury, located within metropolitan Adelaide, South Australia, developed rapidly through urbanisation from the ...Australia has developed extensive policies and guidelines for the management of its water. The City of Salisbury, located within metropolitan Adelaide, South Australia, developed rapidly through urbanisation from the 1970s. Water sensitive urban design principles were adopted to maximise the use of the increased rim-off generated by urbanisation and ameliorate flood risk. Managed aquifer recharge was introduced for storing remediated low-salinity stormwater by aquifer storage and recovery （ASR） in a brackish aquiter for subsequent lrngatlon. Ibis paper outlines now a municipal government has progressively adopted principles of Water Sensitive Urban Design during its development within a framework of evolving national water policies. Salisbury＇s success with stormwater harvesting led to the formation of a pioneering w aterbusiness that includes linking projects from nine sites to provide a non-potable supply of 5 ×10^6 m^3 year. These installations hosted a number of applied research projects addressing well configuration, water quality, reliability and economics and facilitated the evaluation of its system as a potential potable water source. The evaluation showed that while untreated stonnwater contained contaminants, subsurface storage and end-use controls were sufficient to make recovered water sale for public open space irrigation, and with chlorination acceptable lbr third pipe supplies. Drinking water quality could be achieved by adding microfiltration, disinfection with UV and chlorination. The costs that would need to be expended to achieve drinking water safety standards were found to be considerably less than the cost of establishing dual pipe distribution systems. The full cost of supply was determined to be AUD$1.57 m ＂ for non-potable water for pubhc open space lrngatlon much cheaper than mares water, AUD $3.45 m at that time. Producing and storing potable water was found to cost AUDS1.96 to $2.24 m .展开更多
基金sponsored by the National Natural Science Foundation of China (No.50974053)Pennsylvania Service Corporation at Waynesburg,USA
文摘As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.
文摘Australia has developed extensive policies and guidelines for the management of its water. The City of Salisbury, located within metropolitan Adelaide, South Australia, developed rapidly through urbanisation from the 1970s. Water sensitive urban design principles were adopted to maximise the use of the increased rim-off generated by urbanisation and ameliorate flood risk. Managed aquifer recharge was introduced for storing remediated low-salinity stormwater by aquifer storage and recovery （ASR） in a brackish aquiter for subsequent lrngatlon. Ibis paper outlines now a municipal government has progressively adopted principles of Water Sensitive Urban Design during its development within a framework of evolving national water policies. Salisbury＇s success with stormwater harvesting led to the formation of a pioneering w aterbusiness that includes linking projects from nine sites to provide a non-potable supply of 5 ×10^6 m^3 year. These installations hosted a number of applied research projects addressing well configuration, water quality, reliability and economics and facilitated the evaluation of its system as a potential potable water source. The evaluation showed that while untreated stonnwater contained contaminants, subsurface storage and end-use controls were sufficient to make recovered water sale for public open space irrigation, and with chlorination acceptable lbr third pipe supplies. Drinking water quality could be achieved by adding microfiltration, disinfection with UV and chlorination. The costs that would need to be expended to achieve drinking water safety standards were found to be considerably less than the cost of establishing dual pipe distribution systems. The full cost of supply was determined to be AUD$1.57 m ＂ for non-potable water for pubhc open space lrngatlon much cheaper than mares water, AUD $3.45 m at that time. Producing and storing potable water was found to cost AUDS1.96 to $2.24 m .
