【摘要】 为了研究弱固结与松散堰塞体的不同破坏形式,在四川汶川地震灾区分别进行了松散及弱固结堰塞体在自然溢流条件下的破坏试验。通过对堰塞体溃决流量过程与溃决形式进行分析,发现与松散堰塞体相比,弱固结堰塞体溃坝流量的波动性更弱,溃决流量更小;松散堰塞体的溃口形式为宽深型,弱固结堰塞体的溃口形式为窄深型。侵蚀堰塞体并形成溃口的作用力主要包括因流速分布不均形成的剪应力τv和因水流在跌坎旋流运动时形成的陡坎剪应力τe,其中陡坎剪应力起主要作用,当陡坎剪应力与堰塞体临界剪应力达到平衡时,堰塞体达到侵蚀平衡,破坏停止。更多还原

【Abstract】 In order to study different outburst patterns of weakly consolidated and loose barrier dams,the outburst experiments on loose and weakly consolidated dams under natural overflows in the disaster area of Wenchuan Earthquake in Sichuan Province were carried out.The analytic results of discharge process and outburst patterns of barrier dams show that,compared with those of the loose barrier dam,the fluctuation of outburst discharge of the weakly consolidated dam is weaker and the outburst discharge is smaller.The breaches are wide-deep and narrow-deep patterns for loose and weakly consolidated dams,respectively.The forces to erode the barrier dams and to result in breaches mainly include the shear stress τv induced by uneven distribution of water velocity and the headcut shear stress τe resulted from the circulation of water at the headcut.The headcut shear stress τe is dominant,and the barrier dams will reach the erosion equilibrium when the headcut shear stress τe is equal to the critical stress of the barrier dams.更多还原