【摘要】 考虑管道外包混凝土在设计荷载下开裂的影响,采用振型分解反应谱法,研究了重力坝坝后背管在9度地震作用下的自振特性和承载性能规律。研究表明:管道外包混凝土开裂对结构的自振特性影响较小,而对管道钢材应力和管腰截面应力影响较大;高烈度地震作用使背管上弯段至斜直段顶部出现双向裂缝,不利于钢衬与外包混凝土联合承载,同时管坝接缝面和管腰截面呈现较大的拉剪应力状态,不利于管道和坝体的联合承载;坝段间、岸坡坝段与岩体间有可靠的相互约束作用时,横河向地震作用对整体结构的承载性能影响很小。更多还原

【Abstract】 Considering the influence of concrete wall cracking under design load,the behavior of the free vibration and load-carrying properties of penstock laid on downstream face of gravity dam are studied under high-intensity earthquakes.Three conclusions are got from the analysis: the influence of concrete wall cracking on the behavior of the free vibration can be ignored,while the influence on the load effect of penstock itself is notable;there will be in two-direction cracking condition at the upper part of penstock,and there exist unfavorable stress state on the upper part and the waist cross section of the penstock,which are disadvantage to combined loading;the load effect under the high-intensity earthquakes in perpendicular the water flow direction can be ignored when there are reliable constraints among monolith and rock.更多还原