In order to explore the new technology and methods for seismic underground fluid observation,a test study on measurement of hydrogen concentration in fault gas is carried out at the piedmont fault zone of Zhongtiao Mo...In order to explore the new technology and methods for seismic underground fluid observation,a test study on measurement of hydrogen concentration in fault gas is carried out at the piedmont fault zone of Zhongtiao Mountain. Through the experiment on observation positions,gas collection devices and sampling depths,the paper presents the observation method for fault gas hydrogen concentration by using an online automatic trace hydrogen analyzer. Comparative tests are conducted on the stability and optimum conditions of this type of instrument in the field environment, and the hydrogen concentrations at different measuring points of the same fault are observed. The results show that it is technically feasible to carry out continuous hydrogen concentration on a fault zone. The method proposed in this study could be a useful tool for setting the observation points,choosing a reasonable observation depth and scientific analysis of the observed data.展开更多
Experiments of local scouring around three piers were carried out under steady clear-water conditions. We investigated the role of pier spacing and flow rate in scour depth and progression. The scour-hole depth around...Experiments of local scouring around three piers were carried out under steady clear-water conditions. We investigated the role of pier spacing and flow rate in scour depth and progression. The scour-hole depth around the upstream pier was the same as that for single piers and independent of pier spacing. The scour behavior of the middle and downstream piers progressed through a synchronous scouring region, a transition region, and a radical deviation region as the fluid velocity increased. The critical velocity from the synchronous scouring region to the transition region for the middle and downstream piers was the same, which linearly increased with pier spacing. The degree of deviation in the radical deviation region for the middle and downstream piers was dependent on the pier spacing. The critical velocity from the transition region to the radical deviation region for the middle pier increased with the pier spacing. When the spacing was larger than 11 times the diameter of a pier, the scour depths of the three-pier configuration were the same as for the single piers, which indicates the limit of inter-pier fluid–structure interaction. Finally, the data from this study are used to derive adjustment factors to predict the local scour depth around three piers.展开更多
基金funded by the Earthquake Science and Technology Spark Program(XH12006)the Seismological Research Project of China(201208009)
文摘In order to explore the new technology and methods for seismic underground fluid observation,a test study on measurement of hydrogen concentration in fault gas is carried out at the piedmont fault zone of Zhongtiao Mountain. Through the experiment on observation positions,gas collection devices and sampling depths,the paper presents the observation method for fault gas hydrogen concentration by using an online automatic trace hydrogen analyzer. Comparative tests are conducted on the stability and optimum conditions of this type of instrument in the field environment, and the hydrogen concentrations at different measuring points of the same fault are observed. The results show that it is technically feasible to carry out continuous hydrogen concentration on a fault zone. The method proposed in this study could be a useful tool for setting the observation points,choosing a reasonable observation depth and scientific analysis of the observed data.
基金supported by the China National Funds for Distinguished Young Scientists(Grant No.51125034)the National Natural Science Foundation of China(Grant No.51279046)+2 种基金the Fundamental Research Funds for the Central Universities(Grant No.2014B00114)the National Basic Research Program of China(“973”Project)(Grant No.2011CB403303)Colleges and Universities in Jiangsu Province plans to graduate research and innovation(Grant No.146)
文摘Experiments of local scouring around three piers were carried out under steady clear-water conditions. We investigated the role of pier spacing and flow rate in scour depth and progression. The scour-hole depth around the upstream pier was the same as that for single piers and independent of pier spacing. The scour behavior of the middle and downstream piers progressed through a synchronous scouring region, a transition region, and a radical deviation region as the fluid velocity increased. The critical velocity from the synchronous scouring region to the transition region for the middle and downstream piers was the same, which linearly increased with pier spacing. The degree of deviation in the radical deviation region for the middle and downstream piers was dependent on the pier spacing. The critical velocity from the transition region to the radical deviation region for the middle pier increased with the pier spacing. When the spacing was larger than 11 times the diameter of a pier, the scour depths of the three-pier configuration were the same as for the single piers, which indicates the limit of inter-pier fluid–structure interaction. Finally, the data from this study are used to derive adjustment factors to predict the local scour depth around three piers.
