落石冲击下单压式拱形明洞的力学响应
发布时间：2018-08-11 20:59
【摘要】：为进一步了解结构受力情况,为明洞结构设计提供依据,采用动力有限元方法,对客运专线双线单压式拱形明洞落石冲击下结构力学响应进行了研究.首先,以竖直下落冲击为基本工况,从落石与洞顶回填土的相互作用及运动轨迹入手,分析了结构的应力、应变、应变率、位移、速度、加速度等作用效应响应;其次,根据落石、回填土及结构间能量的转化与传递规律,结合结构及基底应力响应,阐述了回填土和混凝土填充材料对落石冲击的缓冲和对结构的保护作用机理,以及边墙形式对基底及仰拱受力的影响;最后进行了45°斜向冲击响应分析并与基本工况进行了对比.研究结果表明:所设计的明洞结构可以承受竖向700 k J的落石冲击能量,拱顶、拱肩及墙身内侧和耳墙墙址等部位是相对受力不利位置,回填方式和直墙式拱墙形式有待进一步研究优化;冲击引起的结构应变率响应介于1×10~(-3)~1×10~(-2)s~(-1),与地震引起的响应范围相同;在本研究工况下,45°斜向冲击作用效应总体上小于竖直冲击.
[Abstract]:In order to further understand the stress of the structure and provide the basis for the structural design of the open tunnel, the dynamic finite element method is used to study the structural mechanical response of the double-line single-pressure arch tunnel under the impact of rock drop. First of all, taking vertical drop impact as the basic working condition, starting with the interaction and motion path of rock fall and roof backfill, the stress, strain rate, displacement, velocity and acceleration of the structure are analyzed. According to the law of energy conversion and transfer between rock fall, backfill and structure, combined with the stress response of structure and basement, the mechanism of cushioning and protecting structure of backfill and concrete filling material to rock drop impact is expounded. The influence of the side wall form on the stress on the base and invert arch is also discussed. Finally, the 45 掳oblique impact response is analyzed and compared with the basic working conditions. The results show that the designed structure can withstand the vertical impact energy of 700kJ, the arch, the shoulder, the inside of the wall and the site of the ear wall are unfavorable relative to the force. The strain rate response caused by impact is between 1 脳 10 ~ (-3) and 1 脳 10 ~ (-2) s ~ (-1), which is the same as that caused by earthquake.
【作者单位】： 西南交通大学土木工程学院;西南交通大学地球科学与环境工程学院;
【基金】：四川省科技计划资助项目(2013GZ0047)
【分类号】：U451
[Abstract]:In order to further understand the stress of the structure and provide the basis for the structural design of the open tunnel, the dynamic finite element method is used to study the structural mechanical response of the double-line single-pressure arch tunnel under the impact of rock drop. First of all, taking vertical drop impact as the basic working condition, starting with the interaction and motion path of rock fall and roof backfill, the stress, strain rate, displacement, velocity and acceleration of the structure are analyzed. According to the law of energy conversion and transfer between rock fall, backfill and structure, combined with the stress response of structure and basement, the mechanism of cushioning and protecting structure of backfill and concrete filling material to rock drop impact is expounded. The influence of the side wall form on the stress on the base and invert arch is also discussed. Finally, the 45 掳oblique impact response is analyzed and compared with the basic working conditions. The results show that the designed structure can withstand the vertical impact energy of 700kJ, the arch, the shoulder, the inside of the wall and the site of the ear wall are unfavorable relative to the force. The strain rate response caused by impact is between 1 脳 10 ~ (-3) and 1 脳 10 ~ (-2) s ~ (-1), which is the same as that caused by earthquake.
【作者单位】： 西南交通大学土木工程学院;西南交通大学地球科学与环境工程学院;
【基金】：四川省科技计划资助项目(2013GZ0047)
【分类号】：U451
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