| 滚石冲击下棚洞破坏动力响应分析及改进对策——以川藏公路（安久拉山南麓）门式棚洞为例 |
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| 引用本文： | 袁博,祝介旺.滚石冲击下棚洞破坏动力响应分析及改进对策——以川藏公路（安久拉山南麓）门式棚洞为例[J].水文地质工程地质,2019,0(6):57-66. |
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| 作者姓名： | 袁博 祝介旺 |
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| 作者单位： | 山东建筑大学土木工程学院，山东 济南250000 |
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| 摘 要： | 位于川藏公路安久拉山南麓的门式防滚石棚洞，在路边高陡边坡滚石冲击下已严重损坏，滚石冲击产生的巨大冲击力导致棚洞纵梁、顶板、梁柱连接处等应力集中部位发生破坏，且滚石冲击后大量堆积在棚顶成为永久荷载。在现场通过卷尺测得棚洞结构尺寸，使用测距仪测得棚顶堆积滚石的最大粒径D=1 m，滚石的最大下落高度H=20 m。为解决门式棚洞存在的安全问题，提出在棚顶设置凹槽并在槽内铺设厚度为10~70 cm、向外坡度为6°的橡胶垫层对原结构进行改造。借助LS-DYNA动力有限元软件按实际尺寸分别建立改进前后的棚洞有限元模型，并模拟改进前后棚洞在滚石冲击最不利工况（H=20 m，D=1 m）下棚洞结构的动力响应，通过数值模拟结果的对比来验证改进后棚洞的受力性能，研究结果发现:改进后的棚洞相对于原棚洞，最大等效应力减小72%、棚顶最大挠度减小45%、落石冲击力减小62%、滚石堆积在棚洞顶板的概率显著降低，说明在棚顶设置起坡橡胶垫层的措施可有效解决目前门式棚洞存在的安全问题。
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| 关 键 词： | 棚洞 滚石 动力响应 优化改造 |
| 收稿时间： | 2019-03-28 |
| 修稿时间： | 2019-05-29 |
Dynamic response analyses and improvement countermeasures of shed-tunnel destruction under rolling stone impact: a case study of the shed-tunnel in the southern foot of the Anjiula Mountain on the Sichuan-Tibet Highway |
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| YUAN Bo,ZHU Jiewang.Dynamic response analyses and improvement countermeasures of shed-tunnel destruction under rolling stone impact: a case study of the shed-tunnel in the southern foot of the Anjiula Mountain on the Sichuan-Tibet Highway[J].Hydrogeology and Engineering Geology,2019,0(6):57-66. |
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| Authors: | YUAN Bo ZHU Jiewang |
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| Institution: | School of Civil Engineering，Shandong Jianzhu University，Jinan，Shandong250000，China |
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| Abstract: | The door-type anti-rolling stone shed-tunnel located at the southern foot of the Anjiula Mountain of the Sichuan-Tibet Highway was seriously damaged under the impact of rolling rocks on the high and steep side slope of the roadside. The huge impact force caused by rolling rocks led to the destruction of the stress concentrated parts of the longitudinal beam, roof and beam-column connection of the shed-tunnel, and after the impact of rolling rocks, a large number of rocks accumulated on the roof of the shed and became permanent loads. The structural dimensions of the shed-tunnel were measured with the tape gauge, and the maximum diameter D=1 m and the maximum falling height H=20 m of the accumulated rolling stones on the roof were measured with a range finder. In order to solve the safety problems of the door-type shed-tunnel, the original structure was reformed by setting grooves on the roof and laying rubber cushion with a thickness of 10-70 cm in the groove and an outward slope of 6 degrees. With the help of LS-DYNA dynamic finite element software, the finite element models of the improved shed-tunnel are established according to the actual size, and the dynamic response of the shed-tunnel under the most disadvantageous conditions (H=20 m, D=1 m) is simulated. The stress performance of the improved shed-tunnel is verified by comparing the numerical simulation results. It is found that the maximum equivalent stress decreases by 72%, the maximum deflection of the roof decreases by 45%, the impact force of falling rocks decreases by 62%, and the probability of rolling rocks accumulating on the roof of the shed-tunnel decreases significantly. The results indicate that the measures of installing rubber cushion on the roof can effectively solve the safety problems existing in the door-type shed-tunnel. |
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