Toppling failure of rock mass/soil slope is an important geological and environmental problem.Clarifying its failure mechanism under different conditions has great significance in engineering.The toppling failure of a...Toppling failure of rock mass/soil slope is an important geological and environmental problem.Clarifying its failure mechanism under different conditions has great significance in engineering.The toppling failure of a cutting slope occurred in a hydropower station in Kyushu,Japan illustrates that the joint characteristic played a significant role in the occurrence of rock slope tipping failure.Thus,in order to consider the mechanical properties of jointed rock mass and the influence of geometric conditions,a simplified analytical approach based on the limit equilibrium method for modeling the flexural toppling of cut rock slopes is proposed to consider the influence of the mechanical properties and geometry condition of jointed rock mass.The theoretical solution is compared with the numerical solution taking Kyushu Hydropower Station in Japan as one case,and it is found that the theoretical solution obtained by the simplified analysis method is consistent with the numerical analytical solution,thus verifying the accuracy of the simplified method.Meanwhile,the Goodman-Bray approach conventionally used in engineering practice is improved according to the analytical results.The results show that the allowable slope angle may be obtained by the improved Goodman-Bray approach considering the joint spacing,the joint frictional angle and the tensile strength of rock mass together.展开更多
为了提高被动电磁装甲对聚能射流的防护性能,对被动电磁装甲对射流的横向偏移作用进行了研究。利用有限元仿真软件,建立了扭曲和装甲结构两个三维有限元模型对射流的变形进行了仿真,最后进行了静态模拟试验与破甲试验,利用直径1 mm铜丝...为了提高被动电磁装甲对聚能射流的防护性能,对被动电磁装甲对射流的横向偏移作用进行了研究。利用有限元仿真软件,建立了扭曲和装甲结构两个三维有限元模型对射流的变形进行了仿真,最后进行了静态模拟试验与破甲试验,利用直径1 mm铜丝进行了模拟实验。结果表明:射流的弯曲不稳定性和电磁装甲产生的横向电磁力都能造成射流产生横向偏移;铜丝模拟实验结果表明,随着充电电压的升高,铜丝横向弯曲越来越严重,当电压升高到5 k V、峰值电流为40 k A时,铜丝出现了断裂;利用破甲弹进行的静破甲试验结果表明,当充电电压升高至2 170 V、峰值电流为50 k A时,射流由于受到横向电磁力作用,后装甲板上射流飞溅的痕迹向一侧发生了偏移。模拟与破甲试验结果进一步证实:随充电电压和峰值电流的升高,被动电磁装甲能够使射流产生更大的横向偏移作用,从而降低射流对装甲的侵彻能力。展开更多
基金Project(52109132)supported by the National Natural Science Foundation of ChinaProject(ZR2020QE270)supported by the Natural Science Foundation of Shandong Province,China+1 种基金Project(JMDPC202204)supported by State Key Laboratory of Strata Intelligent Control,Green Mining Co-founded by Shandong Province and the Ministry of Science and TechnologyShandong University of Science and Technology,China。
文摘Toppling failure of rock mass/soil slope is an important geological and environmental problem.Clarifying its failure mechanism under different conditions has great significance in engineering.The toppling failure of a cutting slope occurred in a hydropower station in Kyushu,Japan illustrates that the joint characteristic played a significant role in the occurrence of rock slope tipping failure.Thus,in order to consider the mechanical properties of jointed rock mass and the influence of geometric conditions,a simplified analytical approach based on the limit equilibrium method for modeling the flexural toppling of cut rock slopes is proposed to consider the influence of the mechanical properties and geometry condition of jointed rock mass.The theoretical solution is compared with the numerical solution taking Kyushu Hydropower Station in Japan as one case,and it is found that the theoretical solution obtained by the simplified analysis method is consistent with the numerical analytical solution,thus verifying the accuracy of the simplified method.Meanwhile,the Goodman-Bray approach conventionally used in engineering practice is improved according to the analytical results.The results show that the allowable slope angle may be obtained by the improved Goodman-Bray approach considering the joint spacing,the joint frictional angle and the tensile strength of rock mass together.
文摘为了提高被动电磁装甲对聚能射流的防护性能,对被动电磁装甲对射流的横向偏移作用进行了研究。利用有限元仿真软件,建立了扭曲和装甲结构两个三维有限元模型对射流的变形进行了仿真,最后进行了静态模拟试验与破甲试验,利用直径1 mm铜丝进行了模拟实验。结果表明:射流的弯曲不稳定性和电磁装甲产生的横向电磁力都能造成射流产生横向偏移;铜丝模拟实验结果表明,随着充电电压的升高,铜丝横向弯曲越来越严重,当电压升高到5 k V、峰值电流为40 k A时,铜丝出现了断裂;利用破甲弹进行的静破甲试验结果表明,当充电电压升高至2 170 V、峰值电流为50 k A时,射流由于受到横向电磁力作用,后装甲板上射流飞溅的痕迹向一侧发生了偏移。模拟与破甲试验结果进一步证实:随充电电压和峰值电流的升高,被动电磁装甲能够使射流产生更大的横向偏移作用,从而降低射流对装甲的侵彻能力。
