中文摘要：

基于经典屈服线理论的机动法,建立虚功方程时考虑了大变形下混凝土板塑性铰线截面处的钢筋伸长做功,提出了计算大变形下混凝土单向板在均布荷载作用下极限承载力的改进机动法.为验证本方法的合理性,开展了3种边界条件的6块钢筋混凝土单向板在大变形下的静载试验,并将试验结果与计算结果进行了对比.结果表明：在大变形下混凝土单向板的破坏模式与经典屈服线理论的塑性铰线模式一致;由于受拉薄膜效应的存在,单向板挠度达到跨度的1/15时,仍能承受较大荷载;本方法计算的板极限承载力与试验结果相差不超过10%,具有较好的精度.

英文摘要：

An improved virtual work method was proposed to calculate the ultimate load-carrying ca- pacity of one-way concrete slabs under uniformly distributed load at large displacements, and its deri- vation was based on the classical yield-line theory. The work, which caused by the extension of steel reinforcements at the sections of plastic hinge line under large displacements, was added in the meth- od. Six one-way slabs with three types of edge conditions were tested to validate the method. Then the theoretical predictions by the method were compared with experimental results. It is shown that the failure mode of the test slabs subjected to large displacement is almost identical with that assumed in the classical yield-line theory. The slabs can carry test load steadily due to the tensile membrane ac- tion, even when their displacements reach 1/15 of the span-length. The predicted load-carrying capac- ity of the method is no more than 10% error compared with the test results, and it shows good accura- cy.