Effectiveness and mechanical characteristics of a pile-beam composite structure in blocking debris flows
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摘要:
以高位泥石流、碎屑流区桩梁组合新型拦挡结构为研究对象, 在总结已有桩梁组合结构的基础上, 运用颗粒流分析仿真程序、通用显示动力分析程序分别对碎屑流冲击下单排、多排桩林及桩梁组合结构拦挡效果、不同位置桩梁组合结构拦挡效果对比模拟以及桩梁组合结构受力特征模拟研究, 探讨了拦挡结构阻挡后碎屑流堆积特征和结构应力传递特征。计算结果表明: 碎屑流中较大粒径颗粒与拦挡结构、两侧沟道边界接触形成的桩-巨石力链拦挡效应可有效阻挡、迟滞后续碎屑流运动, 桩梁组合结构桩-巨石力链拦挡效应最佳; 第一排桩和第二排桩之间改流区进一步抑制了碎屑流速度; 桩梁组合结构在设计布置位置时, 一方面要考虑在碎屑流启动、势动转换过程中尽早抑制碎屑流速度, 另一方面仍需重视库容的设计, 谨防跃顶造成部分碎屑流逃逸, 在上述二者之间选择最优解进行位置布置; 碎屑流巨石冲击桩梁组合结构时, 冲击应力将通过连梁分散传递到后排桩, 连系梁两端连接部分的应力几乎达到屈服强度, 需加强配筋。
Abstract:The pile-beam composite structure in high-elevation debris flow areas is selected as the research object. Based on characterizing the pile-beam composite structure, the particle-flow simulation analysis program and the explicit dynamic analysis program were used to study comparatively the blocking effects of single-row piles and two-row piles, as well as that of a pile-beam composite structure at different positions. Besides, We simulated the mechanical characteristics of the pile-beam composite structure and discussed debris flow accumulation and structural stress transfer after the blocking. The calculation results show that the blocking effect of the pile-boulder force chain formed by the contact between large-size particles in the debris flow with the blocking structure and side boundaries on both sides of the gully could effectively block and delay the subsequent debris flow movement. The blocking effect of the pile-beam composite structure is the best. Meanwhile, the transition zone between the two-row piles further suppressed the flow velocity. When choosing the position for a pile-beam composite structure, we should consider suppressing the debris flow velocity as early as possible at the beginning and the potential energy-kinetic energy conversion process. Meanwhile, we also need to emphasize the design of the reservoir capacity, beware of the escape of debris flow due to a low-head barrier, and choose the optimal solution for the layout. The impact stress by debris flow boulders will be transmitted to the rear pile through the connecting beams, and the connecting parts at both ends of the beam almost reach the yield strength, which needs reinforcement to strengthen.
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表 1 碎屑流及拦挡结构几何参数
Table 1. Geometric parameters for the blocking structures and the debris flow
名称 符号 对应值 初始碎屑流滑体宽度/m a 30 初始碎屑流滑体长度/m b 40 初始碎屑流滑体厚度/m c 10 初始碎屑流所在斜坡转角处与拦挡结构前缘距离/m d 60 初始碎屑流所在斜坡投影长度/m L1 43 碎屑流运动堆积区长度/m L2 81 碎屑流运动堆积区宽度/m M 32 初始碎屑流所在斜坡转角/(°) β 30 拦挡结构高度/m h 12 工况1桩间间距/m n1 5.5 工况2—工况4桩间间距/m n2 3 表 2 碎屑流及拦挡结构参数
Table 2. Dynamic coefficient of the blocking structures and the debris flow
名称 对应值 恢复系数 0.3 静力摩擦系数 0.2 滚动摩擦系数 0.01 碎屑流颗粒密度/(kg·m-3) 2600 碎屑流颗粒弹性模量/GPa 50 表 3 结构与滚石基本参数
Table 3. Basic parameters of the pile-beam composite structure and the boulder
参数 密度/
(kg·m-3)弹模/
GPa泊松比 屈服应力/
MPa失效应变 混凝土 2314 35 0.2 30 0.1 钢筋 7800 200 0.3 400 0.2 碎屑流巨石 2600 50 0.16 — — -
BI Y Z, HE S M, WANG D P, et al., 2017. Discrete-element investigation of rock avalanches impact on the bridge pier[J]. The Chinese Journal of Geological Hazard and Control, 28(4): 16-21. (in Chinese with English abstract) BI Y Z, DU Y J, HE S M, et al., 2018. Numerical analysis of effect of baffle configuration on impact force exerted from rock avalanches[J]. Landslides, 15(5): 1029-1043. doi: 10.1007/s10346-018-0979-z BI Y Z, HE S M, DU Y J, et al., 2019. Effects of the configuration of a baffle-avalanche wall system on rock avalanches in Tibet Zhangmu: discrete element analysis[J]. Bulletin of Engineering Geology and the Environment, 78(4): 2267-2282. doi: 10.1007/s10064-018-1284-8 BIAN J H, LI X Z, XU R C, et al., 2021. Hazard zonation of large-scale landslides along Sichuan—Tibet Railway based on contributing weights model[J]. The Chinese Journal of Geological Hazard and Control, 32(2): 84-93. (in Chinese with English abstract) CHEN G H, HAN P F, WANG Y M, et al., 2022. Discrete element simulation of retaining effect of retaining piles on debris flow of landslide[J]. Journal of Railway Science and Engineering, 19(1): 129-140. (in Chinese with English abstract) CUNDALL P A, STRACK O D L, 1979. A discrete numerical model for granular assemblies[J]. Géotechnique, 29(1): 47-65. doi: 10.1680/geot.1979.29.1.47 GAO Y, LI B, GAO H Y, et al., 2020. Progress and issues in the research of impact and scraping effect of high-elevation and long-runout landslide[J]. Journal of Geomechanics, 26(4): 510-519. (in Chinese with English abstract) GUO C B, LEI W Z, ZHANG Y S, et al., 2006. Main geohazard types and their occurrence characteristics along the Yunnan-Tibetrailway in NW Yunnan[J]. Journal of Geomechanics, 12(2): 228-235. (in Chinese with English abstract) doi: 10.3969/j.issn.1006-6616.2006.02.016 HE S M, YAN S X, DENG Y, et al., 2019. Impact protection of bridge piers against rockfall[J]. Bulletin of Engineering Geology and the Environment, 78(4): 2671-2680. doi: 10.1007/s10064-018-1250-5 HU X D, BI Y H, WEI X P, et al., 2012. An analysis of treatment project of debris flow disaster in Sanyanyu gully of Zhouqu County[J]. Bulletin of Soil and Water Conservation, 32(3): 267-270, 300. (in Chinese with English abstract) LI G B, LUO Y J, 2022. Analysis of dynamic response of reinforced concrete beams based on impact load of RHT model[J]. Journal of Jilin Jianzhu University, 39(1): 11-16. (in Chinese with English abstract) LI R D, MA Z Y, HU X D, 2011. Limit analysis of blocking structure of pile group for Zhouqu debris flow[J]. Gansu Geology, 20(2): 60-65. (in Chinese with English abstract) LI Z, GAO Y, HE K, et al., 2020. Analysis of the fluidization process of the high-position and long-runout landslide in Shuicheng, Liupanshui, Guizhou Province[J]. Journal of Geomechanics, 26(4): 520-532. (in Chinese with English abstract) LIU T J, SUN S Q, ZHAO Z, et al., 2020. Massflow model-based evaluation on effect of engineering treatment of debris flow in Lengzigou Gully[J]. Water Resources and Hydropower Engineering, 51(10): 195-201. (in Chinese with English abstract) LIU Z, LI B, HE K, et al., 2020. An analysis of dynamic response characteristics of the Yigong Landslide in Tibet under strong earthquake[J]. Journal of Geomechanics, 26(4): 471-480. (in Chinese with English abstract) RAN Y H, WANG X L, WANG P, et al., 2018. Experimental study on dynamic performance of concrete filledsteel tubular piles under impact loads[J]. Chinese Journal of Geotechnical Engineering, 40(S1): 81-86. (in Chinese with English abstract) SUN Q C, LIU C Q, ZHOU G D, 2015. Relaxation of granular elasticity[J]. Acta Physica Sinica, 64(23): 236101. (in Chinese with English abstract) doi: 10.7498/aps.64.236101 TAN Y Q, XIAO X W, ZHENG J H, et al., 2016. Effect of outlet diameter of cone-in-cone insert on silo flow pattern[J]. Transactions of the Chinese Society of Agricultural Engineering, 32(19): 82-87. (in Chinese with English abstract) doi: 10.11975/j.issn.1002-6819.2016.19.011 WANG D P, LI Q Z, BI Y Z, et al., 2020. Optimal layout of a new type of baffle based on high-risk areas of rock avalanches[J]. Rock and Soil Mechanics, 41(4): 1323-1332, 1365. (in Chinese with English abstract) WANG J, 2021. Research on the geological disasters remediation project of the Baoji-Chengdu railway[J]. Railway Investigation and Surveying, 47(4): 80-84. (in Chinese with English abstract) WANG P, 2016. Dynamic response analysis and experimental research of concrete-filled steel tubular piles under debris flow[D]. Lanzhou: Lanzhou University of Technology. (in Chinese with English abstract) WANG W P, YIN Y P, ZHU S N, et al., 2020a. Investigation and numerical modeling of the overloading-induced catastrophic rockslide avalanche in Baige, Tibet, China[J]. Bulletin of Engineering Geology and the Environment, 79(4): 1765-1779. doi: 10.1007/s10064-019-01664-2 WANG W P, YIN Y P, YANG L W, et al., 2020b. Investigation and dynamic analysis of the catastrophic rockslide avalanche at Xinmo, Maoxian, after the Wenchuan Ms 8.0 earthquake[J]. Bulletin of Engineering Geology and the Environment, 79(1): 495-512. doi: 10.1007/s10064-019-01557-4 WANG X L, GUAN B L, LI J J, et al., 2015. Dynamic response analysis of "trefoil"-shap unit of concrete-filled steel tubular piles under impact of big stone in debris flow[J]. The Chinese Journal of Geological Hazard and Control, 26(2): 69-75. (in Chinese with English abstract) XU B, 2018. The activity characteristics and engineering prevention and control measures of Gangou debris flow in Longtou town, Ludian county, Yunnan Province[D]. Beijing: China University of Geosciences (Beijing). (in Chinese with English abstract) YANG K C, 2020. Experimental study on control performance of debris flow with pile-group dam[D]. Chengdu: Institute of Mountain Hazards and Environment, University of the Chinese Academy of Sciences. (in Chinese with English abstract) YIN Y P, ZHANG Y S, 2013. Engineering geology analysis of geo-hazards induced by Wenchuan earthquake[M]. Beijing: Science Press. (in Chinese) ZHANG N, 2018. Study on formation mechanism and comprehensive Prevention of Debris flow Disasters in Sanyanyu Valley, Zhouqu[D]. Wuhan: China University of Geosciences. (in Chinese with English abstract) ZHANG W Z, HUANG H F, KONG W, et al., 2018. Failure mode and optimization analysis of pile structure under the impact action of boulders in debris flow[J]. Science Technology and Engineering, 18(4): 15-22. (in Chinese with English abstract) ZOU Z N, WANG Y S, XIN C C, et al., 2019. Analysis on the factors influencing the high level rock avalanches in the Yarlung Zangbo Grand Canyon[J]. The Chinese Journal of Geological Hazard and Control, 30(1): 20-29. (in Chinese with English abstract) 毕钰璋, 何思明, 王东坡, 等, 2017. 碎屑流冲击下的桥墩动力响应特征分析[J]. 中国地质灾害与防治学报, 28(4): 16-21. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGDH201704004.htm 边江豪, 李秀珍, 徐瑞池, 等, 2021. 基于贡献率权重模型的川藏铁路沿线大型滑坡危险性区划[J]. 中国地质灾害与防治学报, 32(2): 84-93. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGDH202102012.htm 陈古华, 韩培锋, 王月明, 等, 2022. 拦挡桩群对滑坡碎屑流挡流效果的离散元模拟[J]. 铁道科学与工程学报, 19(1): 129-140. https://www.cnki.com.cn/Article/CJFDTOTAL-CSTD202201015.htm 高杨, 李滨, 高浩源, 等, 2020. 高位远程滑坡冲击铲刮效应研究进展及问题[J]. 地质力学学报, 26(4): 510-519. doi: 10.12090/j.issn.1006-6616.2020.26.04.044 郭长宝, 雷伟志, 张永双, 等, 2006. 滇藏铁路滇西北段主要地质灾害类型及发育规律的探讨[J]. 地质力学学报, 12(2): 228-235. https://journal.geomech.ac.cn/article/id/9aaf74d3-0a3d-432f-9218-d2c692a883bb 胡向德, 毕远宏, 魏新平, 等, 2012. 舟曲县三眼峪沟泥石流灾害治理工程分析[J]. 水土保持通报, 32(3): 267-270, 300. https://www.cnki.com.cn/Article/CJFDTOTAL-STTB201203056.htm 李广博, 罗乙杰, 2022. 基于RHT模型的冲击荷载作用下钢筋混凝土梁动力响应分析[J]. 吉林建筑大学学报, 39(1): 11-16. https://www.cnki.com.cn/Article/CJFDTOTAL-JLJZ202201003.htm 李瑞冬, 马宗源, 胡向德, 2011. 舟曲泥石流桩林拦挡结构抗冲压极限分析[J]. 甘肃地质, 20(2): 60-65. https://www.cnki.com.cn/Article/CJFDTOTAL-GSDZ201102011.htm 李壮, 高杨, 贺凯, 等, 2020. 贵州省六盘水水城高位远程滑坡流态化运动过程分析[J]. 地质力学学报, 26(4): 520-532. doi: 10.12090/j.issn.1006-6616.2020.26.04.045 刘铁骥, 孙书勤, 赵峥, 等, 2020. 基于Massflow模型的冷渍沟泥石流工程治理效果评价[J]. 水利水电技术, 51(10): 195-201. https://www.cnki.com.cn/Article/CJFDTOTAL-SJWJ202010024.htm 刘铮, 李滨, 贺凯, 等, 2020. 地震作用下西藏易贡滑坡动力响应特征分析[J]. 地质力学学报, 26(4): 471-480. doi: 10.12090/j.issn.1006-6616.2020.26.04.040 冉永红, 王秀丽, 王朋, 等, 2018. 冲击荷载下钢管混凝土桩林动力性能试验研究[J]. 岩土工程学报, 40(S1): 81-86. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2018S1014.htm 孙其诚, 刘传奇, 周公旦, 2015. 颗粒介质弹性的弛豫[J]. 物理学报, 64(23): 236101. https://www.cnki.com.cn/Article/CJFDTOTAL-WLXB201523029.htm 谭援强, 肖湘武, 郑军辉, 等, 2016. 锥形改流体下部孔径对筒仓卸料流态的影响[J]. 农业工程学报, 32(19): 82-87. https://www.cnki.com.cn/Article/CJFDTOTAL-NYGU201619011.htm 王东坡, 李沁泽, 毕钰璋, 等, 2020. 碎屑流高风险区桩群防护结构优化布局研究[J]. 岩土力学, 41(4): 1323-1332, 1365. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202004024.htm 王靖, 2021. 宝成铁路地质灾害整治工程方案研究[J]. 铁道勘察, 47(4): 80-84. https://www.cnki.com.cn/Article/CJFDTOTAL-TLHC202104016.htm 王朋, 2016. 泥石流作用下钢管混凝土桩林结构动力响应分析与试验研究[D]. 兰州: 兰州理工大学. 王秀丽, 关彬林, 李俊杰, 2015. 泥石流块石冲击下新型钢管混凝土桩林坝"品"单元动力响应分析[J]. 中国地质灾害与防治学报, 26(2): 69-75. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGDH201502012.htm 许彬, 2018. 云南鲁甸龙头山集镇甘沟泥石流活动特征与防治对策[D]. 北京: 中国地质大学(北京). 杨开成, 2020. 桩林坝调控泥石流的性能实验研究[D]. 成都: 中国科学院大学(中国科学院水利部成都山地灾害与环境研究所). 殷跃平, 张永双, 2013. 汶川地震工程地质与地质灾害[M]. 北京: 科学出版社. 张楠, 2018. 舟曲三眼峪沟泥石流灾害形成机理及综合防治研究[D]. 武汉: 中国地质大学. 张万泽, 黄海峰, 孔伟, 等, 2018. 泥石流大块石冲击作用下桩林结构的破坏形式及其优化分析[J]. 科学技术与工程, 18(4): 15-22. https://www.cnki.com.cn/Article/CJFDTOTAL-KXJS201804003.htm 邹子南, 王运生, 辛聪聪, 等, 2019. 雅鲁藏布大峡谷高位岩质崩塌影响因素分析[J]. 中国地质灾害与防治学报, 30(1): 20-29. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGDH201901003.htm