The siphon drainage is an effective measure for the slope groundwater control. However,for the traditional siphon drainage, limitations such as siphon lift restriction and poor reliability in longterm service prevent ...The siphon drainage is an effective measure for the slope groundwater control. However,for the traditional siphon drainage, limitations such as siphon lift restriction and poor reliability in longterm service prevent it from being widely used. In this study, an improved siphon drainage method with inclined borehole penetrating the deep part of the slope is proposed to overcome the limitations suffered by the traditional method. Through experimental research, theoretical analysis and engineering practice,the reliability and capability of the proposed method are investigated. The results demonstrate that with the inclined pipe the height difference between the control point of the groundwater level and the orifice can be controlled to be less than the height of the water column corresponding to the local atmospheric pressure. As a result, deep drainage can be achieved.In addition, by controlling the diameter of siphon drainage pipe not larger than 4 mm, a plug flow can be formed in the siphon pipe, which can prevent air accumulation in the siphon process and a continuous and effective siphon drainage is achieved. Through a practical project running smoothly since September 2013, it is found that the proposed method can effectively drain the groundwater deep in the slope and the maximum drawdown of groundwater level in boreholes can reach 8.5 m with an average drainage flow of 5.5 m3/d. The practical results also illustrate that 4 mm siphon pipe can be used to realize deep slope drainage and restart siphon automatically.展开更多
The space-based laser interferometers,LISA,Taiji and TianQin,are targeting to observe milliHz gravitational waves(GWs)in the 2030s.The joint observations from multiple space-based detectors yield significant advantage...The space-based laser interferometers,LISA,Taiji and TianQin,are targeting to observe milliHz gravitational waves(GWs)in the 2030s.The joint observations from multiple space-based detectors yield significant advantages.In this work,we recap the studies and investigations for the joint space-based GW detector networks to highlight:1)the high precision of sky localization for the massive binary black hole(BBH)coalescences and the GW sirens in the cosmological implication,2)the effectiveness to test the parity violation in the stochastic GW background observations,3)the efficiency of subtracting galactic foreground,4)the improvement in stellar-mass BBH observations.We inspect alternative networks by trading off massive BBH observations and stochastic GW background observation.展开更多
基金financially supported by the National Key R&D Program of China (Grant No. 2018YFC1504704)the National Natural Science Foundation of China (Grant No. 41772276)Key R&D project of Zhejiang Province (Grant No. 2017C03006)
文摘The siphon drainage is an effective measure for the slope groundwater control. However,for the traditional siphon drainage, limitations such as siphon lift restriction and poor reliability in longterm service prevent it from being widely used. In this study, an improved siphon drainage method with inclined borehole penetrating the deep part of the slope is proposed to overcome the limitations suffered by the traditional method. Through experimental research, theoretical analysis and engineering practice,the reliability and capability of the proposed method are investigated. The results demonstrate that with the inclined pipe the height difference between the control point of the groundwater level and the orifice can be controlled to be less than the height of the water column corresponding to the local atmospheric pressure. As a result, deep drainage can be achieved.In addition, by controlling the diameter of siphon drainage pipe not larger than 4 mm, a plug flow can be formed in the siphon pipe, which can prevent air accumulation in the siphon process and a continuous and effective siphon drainage is achieved. Through a practical project running smoothly since September 2013, it is found that the proposed method can effectively drain the groundwater deep in the slope and the maximum drawdown of groundwater level in boreholes can reach 8.5 m with an average drainage flow of 5.5 m3/d. The practical results also illustrate that 4 mm siphon pipe can be used to realize deep slope drainage and restart siphon automatically.
基金supported in part by the National Natural Science Foundation of China(11821505)supported in part by the National Key Research and Development Program of China(2020YFC2201501)+7 种基金in part by the National Natural Science Foundation of China(12075297 and 12235019)supported in part by the National Key R&D Program of China(2021YFC2203001)supported by the National Natural Science Foundation of China(12147132)supported by the National Key Program for Science and Technology Research and Development(2020YFC2201400,2022YFC2205201)supported in part by the National Key R&D Program of China under(2021YFC2201901)supported in part by JSPS Kakenhi Grant-in-Aid for Scientific Research(17H06358,19K03870 and 23K03385)supported by the National Key R&D Program of China(2021YFC2201903)National Natural Science Foundation of China(12003059).
文摘The space-based laser interferometers,LISA,Taiji and TianQin,are targeting to observe milliHz gravitational waves(GWs)in the 2030s.The joint observations from multiple space-based detectors yield significant advantages.In this work,we recap the studies and investigations for the joint space-based GW detector networks to highlight:1)the high precision of sky localization for the massive binary black hole(BBH)coalescences and the GW sirens in the cosmological implication,2)the effectiveness to test the parity violation in the stochastic GW background observations,3)the efficiency of subtracting galactic foreground,4)the improvement in stellar-mass BBH observations.We inspect alternative networks by trading off massive BBH observations and stochastic GW background observation.
