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Behavior of traditional concrete dams and three-dimensional printed concrete dams under the debris flow impact

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Journal of Mountain Science 2023年第12期20卷 3703-3717页

作者： MEREE Hani YAN Shuai-xing wang dong-po BI Yu-zhang State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Resources and Environment Fujian Agriculture and Forestry UniversityFuzhou 350002China

This study investigated the resilience of traditional concrete dams compared to 3D printed concrete dams(3DPC)when subjected to debris *** types of dams,namely check dams,arch dams,and curve dams,were numerically analyzed using a three-dimensional Coupled Eulerian-Lagrangian(CEL)*** research focused on critical factors such as impact force and viscous energy dissipation to compare dam ***,the study examined the printing and service phases of 3DPC models,determining potential failure modes and analyzing printing *** results demonstrated that 3DPC dams outperformed traditional concrete dams,with filament deposition orientation,perpendicular to the debris flow direction,identified as a pivotal *** percentage and pattern were also found to influence the behavior of 3DPC ***,curved dams exhibited superior performance based on dam *** findings have significant potential for advancing the development of resilient dam structures capable of withstanding debris flow impacts.

关键词： Dam geometry Impact force Printing process Viscous dissipation Coupled Eulerian-Lagrangian Three-dimensional printed concrete

Rock characteristics and dynamic fragmentation process of the 2018 Daanshan rockslide in Beijing,China

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Journal of Mountain Science 2023年第2期20卷 448-465页

作者： FAN Tian-zhen AN Hui-cong OUYANG Chao-jun wang dong-po State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China Key laboratory of Mountain Hazards and Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

This study investigated the failure mechanism associated with the rock mass structure and the dynamic fragmentation process of blocky rocks of the 2018 Daanshan rockslide that occurred on 11 August,*** was found that the initially collapsed rock of this rockslide was partitioned along the unconformity and strata *** analyzed how the unique rock mass structure,coupled with the road cut and the antecedent rainfall,jointly resulted in its *** on the rock types and geological structures,the initial stratified configuration of a discrete element model was setup to reveal the influences of the local *** numerical model was divided into three *** 1 is the basalt of the Nandaling Formation,the normal and shear stiffnesses of the basalt particles are set as 80 MPa and 40 *** 2 and 3 are the sandstones interbedded with mudstone and sandstone of the Shihezi Formation,and the normal and shear stiffnesses of these parts were set as 6 MPa and 10 MPa,*** dynamic process of the rockslide,particularly the rock fragmentation process,was numerically analyzed using a 3D discrete element *** numerical results were compared with real-time videos and field *** results show that the rock fragmentation and the final deposition range match well with the real disaster phenomenon,and the calculation accuracy of the rockslide reaches 82.41%.Moreover,a parameter sensitivity analysis was conducted,and classical uniform models under different bonding forces were established;the stratified model can better restore the true state of the fragmentation,movement,and deposition processes of ***,for complicated rocks with significant differences in lithology,clarifying the rock mass stratigraphy is essential for an accurate reconstruction of the dynamic process of rockslides.

关键词： Discrete element method Rockslide Stratified model Numerical modeling Fragmentation Daanshan rockslide

Optimal array layout of cylindrical baffles to reduce energy of rock avalanche

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Journal of Mountain Science 2022年第2期19卷 493-512页

作者： BI Yu-zhang wang dong-po FU Xian-lei LIN Yi-xiong SUN Xin-po JIANG Zhe-yuan B-Z geotechnical Company Nanjing 210096China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Civil Engineering Sichuan University of Science and EngineeringZigong 643000China Jiangsu Key Laboratory of Urban Underground Engineering&Environmental Safety Institute of Geotechnical EngineeringSoutheast UniversityNanjing 210096China

The array of baffles protection structure is a flow resistance structure with good drainage,blocking,and intercepting effects on the rock *** this research,the physical model test on rock avalanches was *** parameters(column spacing,row spacing,and a number of baffles)were used as indicators to determine the optimal layout of the array of baffles for energy efficiency consumption ***,the lattice Boltzmann numerical simulation method was used to build a numerical simulation model of rock avalanches-array of the baffles-hazard-bearing body to obtain the rock’s velocity attenuation and flow trajectory avalanches in the impact baffle protection ***,the results of the physical model test and the numerical simulation were mutually *** following conclusions were drawn through two methods of physical model test and numerical simulation.(1)The optimal layout parameters of array of baffles were determined as three rows of array of baffles(The number of baffles in each row is 7,8,9),column spacing Sc=3.5,and row spacing Sr=4.5.(2)Under the conditions of high baffle density(such as Sc=1.5,2.5),the rock avalanches would produce a certain degree of circumfluence,which would increase the fluid velocity by at least 24.5% over the average velocity,so the column spacing density should be increased appropriately to achieve the optimal effect of reducing the energy of rock avalanches.(3)In the event of a prototype grooved rock avalanches with a velocity close to 24.5 m/s and a flow depth of about 1.5 m,the three-row array of baffles protection with the parameters Sc^(*)=1.18 m and Sr^(*)=1.51 m could be arranged,playing the role of optimizing the array of baffles to guide the flow and block the energy *** experiments can be used to replace laboratory experiments to some *** Lattice Boltzmann method-Discrete element method(LBM-DEM)studies are required before applications to practical engineering.

关键词： Lattice Boltzmann Physical model Numerical simulation Energy consumption optimization

Numerical investigation of effects of “baffles-deceleration strip” hybrid system on rock avalanches

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Journal of Mountain Science 2019年第2期16卷 414-427页

作者： BI Yu-zhang HE Si-ming DU Yan-jun SHAN Jie YAN Shuai-xing wang dong-po SUN Xin-po Institute of Geotechnical Engineering of Southeast University School of Transportation Southeast University Key Laboratory of Mountain Hazards and Surface Process Chinese Academy of Sciences Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chinese Academy of Sciences Center for Excellence in Tibet Plateau Earth Sciences University of Chinese Academy of Sciences State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology College of civil engineering Sichuan University of Science and Engineering

Arrays of baffles are usually installed in front of protection site to attenuate the flow energy of rock avalanches in mountainous areas. Optimization design is crucial for efficiency promotion in hazard energy dissipation engineering. In this study, a deceleration strip was added in the baffles protection system to optimize the traditional baffles system. The effects of the "baffles-deceleration strip" hybrid protection system was discussed in detail with the nails number and nails angle. This study presents details of numerical experiments using the discreteelement method(DEM). The effect of the optimization of hybrid protection system(nail angle and nail number) were investigated specifically, especially the impact force that avalanches exerted on structures. The results show that the maximum impact forces and kinetic energy of the rock avalanches decreases with the increase of the number and angle of the nail. Moreover, the distance between the toe and the bearing structure(L_m) is also a key factor. The shorter the distance L_m(30 m) is, the higher the maximum impact force are. The longer the distance L_m(70 m) is, the lower the maximum impact force are. Under the same size of the nails, increasing the numbers can enhance the dissipation ability of the hybrid protection system. Meanwhile, increasing itsangle can also enhance the dissipation ability. There are three key ways for nails attenuate rock avalanches:(i) block the fine particles directly;(ii) form the particles bridge between nails and baffles;(iii) dissipate the coarse particles energy directly. The effect of segregation in rock avalanches is crucial for the energy dissipation mechanism, which is a key factor to optimize the traditional baffle system.

关键词： Rock avalanches Baffles Hybrid system Energy dissipation Impact force

On the initiation,movement and deposition of a large landslide in Maoxian County,China

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Journal of Mountain Science 2018年第6期15卷 1319-1330页

作者： pei xiang-jun guo bin cui sheng-hua wang dong-po xu qiang li tian-tao State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China

At 5 am 24 th June 2017, a catastrophic landslide hit Xinmo Village, Maoxian County, Sichuan Province, China. The slide mass rushed down from an altitude of 3400 m and traveled 2700 m in a high velocity. The 13 million m^3 deposition buried the whole village and caused about 100 deaths. The source area of the landslide is located in a high steep slope, average slope angle is 40o and maximal angle is 65o. The strata are interbedded Triassic Zagunao Formation metamorphic sandstone and slate with the dip slope angle of 45°. Based on high-resolution satellite remote sensing image, UAV image, DEM data, and field investigation, failure mechanism, travel features, and deposit characteristics were analyzed. The results showed that this landslide was influenced by Songpinggou Fault zone. According to the topography before the failure, the landslide is located in the back scarp of an antecedent landslide induced by Diexi Earthquake in 1933. The bedding slope provided potential rupture surface. Historical seismic activities and long-term gravitational deformation caused rock mass accumulated damages. Weathering and precipitation weakened the rock mass and finally induced shearing and tension failure. A huge block detached from the top rock slope, pushed the past landslide deposits in the middle part, rushed out of the slope bottom in a high velocity and buried the Xinmo Village. The rapid movement entrained and brought the soil into the Songping Gully which recoiled with and bounced back from the opposite mountain.

关键词： Xinmo landslide Seismic damages Longrunout Failure mechanism Rock fragment

Numerical modeling and dynamic analysis of the 2017 Xinmo landslide in Maoxian County, China

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Journal of Mountain Science 2017年第9期14卷 1701-1711页

作者： OUYANG Chao-jun ZHAO Wei HE Si-ming wang dong-po ZHOU Shu AN Hui-cong wang Zhong-wen CHENG Duo-xiang Key laboratory of Mountain Hazards and Surface Process &Institute of Mountain Hazards and Environment (IMHE) Chinese Academy of Sciences Chengdu 610041 China University of Chinese Academy of Sciences Beijing 100049 China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences Beijing 100101 China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610o59 China Sichuan Engineering Research Center for Emergency Mapping & Disaster Reduction/Sichuan Geomatics Center Chengdu 610041 China

A catastrophic landslide occurred at Xinmo village in Maoxian County, Sichuan Province,China, on June 24, 2017. A 2.87×106 m3 rock mass collapsed and entrained the surface soil layer along the landslide path. Eighty-three people were killed or went missing and more than 103 houses were destroyed. In this paper, the geological conditions of the landslide are analyzed via field investigation and high-resolution imagery. The dynamic process and runout characteristics of the landslide are numerically analyzed using a depth-integrated continuum method and Mac Cormack-TVD finite difference *** results show that the evaluated area of the danger zone matchs well with the results of field investigation. It is worth noting that soil sprayed by the high-speed blast needs to be taken into account for such kind of large high-locality landslide. The maximum velocity is about 55 m/s, which is consistent with most cases. In addition, the potential danger zone of an unstable block is evaluated. The potential risk area evaluated by the efficient depthintegrated continuum method could play a significant role in disaster prevention and secondary hazard avoidance during rescue operations.

关键词： Xinmo landslide Runout Numerical modeling Dynamic process potential risk Highlocality landslide

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超声冲击法提高焊接接头疲劳强度的机理分析

天津大学学报 2007年第5期40卷 623-628页

作者：王东坡周达天津大学材料科学与工程学院天津300072

使用工具显微镜和维氏硬度计测量了超声冲击处理前后焊趾区的几何形状与硬度的变化,并应用疲劳缺口系数的概念及Dang Van准则,对超声冲击造成的焊趾区几何形状的变化及残余压缩应力对接头疲劳性能改善的影响行为进行了研究.结果表明,对... 详细信息

使用工具显微镜和维氏硬度计测量了超声冲击处理前后焊趾区的几何形状与硬度的变化,并应用疲劳缺口系数的概念及Dang Van准则,对超声冲击造成的焊趾区几何形状的变化及残余压缩应力对接头疲劳性能改善的影响行为进行了研究.结果表明,对于低中强钢来说,超声冲击处理焊接接头疲劳性能的改善主要是由焊趾部位形成的残余压应力及改善焊趾几何外形这两个因素引起的,硬化的作用相比次之.研究还证明,冲击处理对焊接接头应力集中程度的降低,主要是通过增加焊趾区过渡半径来实现的.

关键词：焊接接头疲劳强度超声冲击处理机理 Dang Van准则

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泥石流冲击弧形拦挡坝动力响应研究

岩土力学 2020年第12期41卷 3851-3861页

作者：王东坡张小梅成都理工大学地质灾害防治与地质环境保护国家重点实验室四川成都610059

泥石流冲击过程中,坝基位置处承受了较大冲击力,易引起该位置出现应力集中而导致局部冲击破坏。为此,将竖向拦挡坝结构优化为弧形拦挡坝,并基于动量及能量守恒开展泥石流冲击弧形拦挡坝理论计算研究,推导泥石流对弧形拦挡坝的冲击力及... 详细信息

泥石流冲击过程中,坝基位置处承受了较大冲击力,易引起该位置出现应力集中而导致局部冲击破坏。为此,将竖向拦挡坝结构优化为弧形拦挡坝,并基于动量及能量守恒开展泥石流冲击弧形拦挡坝理论计算研究,推导泥石流对弧形拦挡坝的冲击力及爬升高度计算公式。为验证理论公式的正确性,进一步开展泥石流冲击弧形拦挡坝物理模型试验。研究结果表明:物理模型试验结果与所推导的理论公式计算结果具有较高的拟合度,该理论公式可适用于泥石流对弧形拦挡坝的冲击计算;泥石流流速、冲击力、爬升高度与泥石流沟道纵坡坡度呈正相关关系;冲击力及爬升高度主要受弗洛德数Fr、泥石流沟道纵坡坡度α、拦挡坝弧形半径R控制,并与Fr呈二次方正相关,与泥石流沟道纵坡坡度α的余弦值成反比;与竖向型拦挡坝结构相比,弧形拦挡坝结构在爬升高度上无显著影响,然而可较大程度降低泥石流对坝体的法向冲击力,局部结构增强也使得坝体结构强度得到提升。该研究可为泥石流拦挡坝工程的结构设计提供理论及技术支持。

关键词：泥石流弧形拦挡坝冲击力爬升高度

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超声冲击法提高T型焊接管接头疲劳性能

天津大学学报 2006年第6期39卷 757-762页

作者：王东坡尹丹青天津大学材料科学与工程学院天津300072

为了提高T型管接头疲劳性能,提出采用超声冲击方法对具有相同级别的低碳钢和奥氏体不锈钢 1Cr18Ni9Ti钢管接头进行疲劳性能对比试验．结果表明:超声冲击处理低碳钢后疲劳强度提高67％左右,疲劳寿命延长了22-45倍;超声冲击处理奥氏体不锈... 详细信息

为了提高T型管接头疲劳性能,提出采用超声冲击方法对具有相同级别的低碳钢和奥氏体不锈钢 1Cr18Ni9Ti钢管接头进行疲劳性能对比试验．结果表明:超声冲击处理低碳钢后疲劳强度提高67％左右,疲劳寿命延长了22-45倍;超声冲击处理奥氏体不锈钢1Cr18Ni9Ti疲劳强度提高69％左右,疲劳寿命延长了21-30倍．在低应力比R(R≤0)条件下使用超声冲击处理技术能够大幅度改善管接头的疲劳性能．将超声冲击处理方法用于提高具有相同强度级别的不锈钢和普通碳素结构钢管接头疲劳性能的效果相差不大．超声冲击法对提高疲劳强度效果显著．

关键词：超声冲击处理管接头疲劳性能不锈钢低碳钢