【摘要】 为正确评估震后地下防护结构的抗动载能力,对汶川地震地下防护结构的破坏状况进行了分析,根据结构震后破坏模式建立了相应的结构损伤力学模型,提出了震前固端拱在震后劣化为三铰拱的结构分析方法。针对不同结构型式,给出了动荷载动力系数的确定方法,通过计算得到了在相同均布荷载作用下地下拱形结构的弯矩和拱脚推力的计算公式。针对具体实例,计算了不同损伤型式的拱结构承受冲击波荷载时的结构内力,从而给出了震后结构的抗动载能力评估方法。研究表明,地下防护结构震后抗冲击能力下降可达50%以上。更多还原

【Abstract】 Based on the investigation on the aseismic damage of underground structures in Wenchuan earthquake,the main damage modes of underground protective arch structures were summarized.Simplified structural models for damaged arches,including two-hinged and three-hinged arches,were built according to the damage modes and distributions.Residual dynamic resistances of seismic damaged underground arches were calculated by equivalent static load method.Through case studies,moments of arches with different constraints were analyzed under shock wave load,as well as the thrust force at the foot of the arches.Then the ability of anti-dynamic load of the damaged structure after eartheuake was evaluated.It is concluded that the load capapcity of the damaged arch drops by 16 per cent or even 50 per cent when controled by bending or shear resistance,respectively.更多还原