The estimation of residual displacements in a structure due to an anticipated earthquake event has increasingly become an important component of performance-based earthquake engineering because controlling these displ...The estimation of residual displacements in a structure due to an anticipated earthquake event has increasingly become an important component of performance-based earthquake engineering because controlling these displacements plays an important role in ensuring cost-feasible or cost-effective repairs in a damaged structure after the event.An attempt is made in this study to obtain statistical estimates of constant-ductility residual displacement spectra for bilinear and pinching oscillators with 5%initial damping,directly in terms of easily available seismological,site,and model parameters.None of the available models for the bilinear and pinching oscillators are useful when design spectra for a seismic hazard at a site are not available.The statistical estimates of a residual displacement spectrum are proposed in terms of earthquake magnitude,epicentral distance,site geology parameter,and three model parameters for a given set of ductility demand and a hysteretic energy capacity coefficient in the case of bilinear and pinching models,as well as for a given set of pinching parameters for displacement and strength at the breakpoint in the case of pinching model alone.The proposed scaling model is applicable to horizontal ground motions in the western U.S.for earthquake magnitudes less than 7 or epicentral distances greater than 20 km.展开更多
针对稠油热采存在油汽比低、能耗大、CO_(2)排放高以及稠油冷采采出液难处理等问题,采用自制的降黏驱油剂ODA1配制驱替液,对其进行了静态降黏评价、性能分析以及特稠油冷采物理模拟实验研究。结果表明:提高驱替液中ODA1的质量分数和矿化...针对稠油热采存在油汽比低、能耗大、CO_(2)排放高以及稠油冷采采出液难处理等问题,采用自制的降黏驱油剂ODA1配制驱替液,对其进行了静态降黏评价、性能分析以及特稠油冷采物理模拟实验研究。结果表明:提高驱替液中ODA1的质量分数和矿化度,均能有效降低稠油黏度;当驱替液中ODA1质量分数为2%、矿化度为100 g/L时,特稠油与驱替液以质量比为0.5混合后的降黏率达到了70.62%;特稠油在驱替液表面自发扩散,油水自动分相,完全不乳化。在渗透率约为1 000×10^(-3)μm^(2)、地层温度为40℃、特稠油黏度为11 600 m Pa·s条件下进行模拟驱油实验,驱替液驱的采出程度较模拟地层水驱采出程度提高了6.31百分点;水驱后驱替液依次进行转驱、第1次闷井和第2次闷井,采出程度分别提高了7.48、11.70和7.83百分点,合计较水驱提高了27.02百分点,采出稠油在40℃条件下的黏度降至3 553 m Pa·s,降黏率达61.37%,驱替液具有边驱油边降黏的特点。同时在冷采过程中无碳排放,采出水无污染,可循环利用。研究成果为特稠油绿色冷采提供了一种新的技术思路。展开更多
文摘The estimation of residual displacements in a structure due to an anticipated earthquake event has increasingly become an important component of performance-based earthquake engineering because controlling these displacements plays an important role in ensuring cost-feasible or cost-effective repairs in a damaged structure after the event.An attempt is made in this study to obtain statistical estimates of constant-ductility residual displacement spectra for bilinear and pinching oscillators with 5%initial damping,directly in terms of easily available seismological,site,and model parameters.None of the available models for the bilinear and pinching oscillators are useful when design spectra for a seismic hazard at a site are not available.The statistical estimates of a residual displacement spectrum are proposed in terms of earthquake magnitude,epicentral distance,site geology parameter,and three model parameters for a given set of ductility demand and a hysteretic energy capacity coefficient in the case of bilinear and pinching models,as well as for a given set of pinching parameters for displacement and strength at the breakpoint in the case of pinching model alone.The proposed scaling model is applicable to horizontal ground motions in the western U.S.for earthquake magnitudes less than 7 or epicentral distances greater than 20 km.
文摘针对稠油热采存在油汽比低、能耗大、CO_(2)排放高以及稠油冷采采出液难处理等问题,采用自制的降黏驱油剂ODA1配制驱替液,对其进行了静态降黏评价、性能分析以及特稠油冷采物理模拟实验研究。结果表明:提高驱替液中ODA1的质量分数和矿化度,均能有效降低稠油黏度;当驱替液中ODA1质量分数为2%、矿化度为100 g/L时,特稠油与驱替液以质量比为0.5混合后的降黏率达到了70.62%;特稠油在驱替液表面自发扩散,油水自动分相,完全不乳化。在渗透率约为1 000×10^(-3)μm^(2)、地层温度为40℃、特稠油黏度为11 600 m Pa·s条件下进行模拟驱油实验,驱替液驱的采出程度较模拟地层水驱采出程度提高了6.31百分点;水驱后驱替液依次进行转驱、第1次闷井和第2次闷井,采出程度分别提高了7.48、11.70和7.83百分点,合计较水驱提高了27.02百分点,采出稠油在40℃条件下的黏度降至3 553 m Pa·s,降黏率达61.37%,驱替液具有边驱油边降黏的特点。同时在冷采过程中无碳排放,采出水无污染,可循环利用。研究成果为特稠油绿色冷采提供了一种新的技术思路。
