非均布荷载作用下震后地下拱结构抗动载能力评估

RESIDUAL DYNAMIC RESISTANCE ASSESSMENT OF SEISMIC DAMAGED UNDERGROUND ARCH UNDER NON-UNIFORM EXPLOSION LOADING

为评估非均布荷载作用下震后地下防护结构的抗动载能力,针对震前震后三种结构型式,给出了动荷载动力系数的确定方法,推导出了非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。针对工程实例,计算了不同损伤型式的拱结构承受非均布动载时的结构内力,从而给出了非均布荷载作用下震后结构的抗动载能力评估方法。研究表明:抗弯设计条件下震后拱结构抗非均布动载能力将降低约13%,而在抗剪设计条件下由于裂缝的穿透震后拱结构抗非均布动载能力将降低50%以上。

For the sake of the ability assesment of anti non-uniform dynamic loading of the damaged structure after earthquake, 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 an equivalent static load method. Through an example, moments of arches with different constraints were calculated under non-uniform explosion loading, as well as the thrust force at the foot of the arches. Then the ability of anti-dynamic loads of the damaged structure after eartheuake was evaluated. It is concluded that under non-uniform explosion loading the load capapcity of the damaged arch drops at a level of 13 percent or even 50 percent when controled by bending or shear resistance, respectively.