路堑堆积层滑坡变形失稳诱发因素及形成机制分析

通江县路堑滑坡为第四系崩坡积堆积层,根据调查分析,诱发滑坡失稳主要因素包括雨水的渗入、松散坡体结构以及岩土力学性质,尤其是基覆界面泥化夹层遇水软化特征。其形成机制概括为：由于道路施工及弃渣堆放,改变了地表水径流系统,使得雨水进入滑坡后缘,增加坡体重度,降低了滑带力学性质,诱发滑坡发生推移式变形失稳。针对该堆积层滑坡特征,提出了治理方案。     

地下水在三峡库区堆积层滑坡中的作用

结合三峡库区堆积层滑坡中地下水的类型及特点,指出地下水对堆积层滑坡的影响主要有三种作用:物理作用、化学作用和力学作用,并分析了地下水对堆积层滑坡稳定性的影响,这对堆积层滑坡进行有效防治具有重要意义.     

地震作用下堆积层斜坡动力响应规律研究

运用有限差分软件FLAC3D建立数值模型,分析了堆积层滑坡在不同地震波条件下,自身地形地貌条件对其加速度场的影响和变形破坏特征,揭示动荷载作用下堆积层斜坡的动力响应规律.     

秦岭山区某堆积层滑坡形成机制及稳定性评价

结合秦岭山区某堆积层滑坡稳定性研究项目,探讨了该滑坡的形成机制和发展趋势,并从定性及定量角度分析了滑坡的稳定性,根据该滑坡的实际情况,提出了削坡、抗滑桩、挡土墙等综合治理方案,为类似工程提供了借鉴。     

堆积层边坡位移矢量角的形成作用机制及其与稳定性演化关系的研究

通过对堆积层边坡不同稳定性演化阶段的变形性质和基本构成的分析，发现堆积层边坡表层位移矢量角是由整体滑移矢量角、压缩位移矢量角、塑性变形位移矢量角及蠕动变形矢量角构成。且其构成比例是随着边坡的不同位置及不同稳定性演化阶段而变化。同时，对表层位移矢量角在堆积层边坡不同稳定性演化阶段的形成作用机制进行了深入分析与探讨，分别建立了堆积层边坡压缩变形阶段和塑性变形阶段的表层位移矢量角与相应位移速率及其他参数的定量关系，总结了位移矢量角在不同演化阶段及不同部位的变化规律。最后运用新滩滑坡不同演化阶段的实际位移监测资料进行了验证分析，发现新滩边坡稳定性不同，则演化阶段的坡体位移矢量角具有不同变化规律，而且这些动态变化规律与该边坡实际变形失稳阶段相吻合。     

隧道穿越古滑坡堆积层关键施工技术

基于青冈山长公路隧道西口穿越古滑坡堆积层的工程条件,提出了有效的加固措施,通过分析监控量测的数据,证明了该方法的可靠性,确保了隧道安全通过古滑坡堆积层.     

甘肃省白龙江流域典型高位堆积层滑坡成因机制研究及其危险性预测

以甘肃省白龙江流域武都区泻流坡滑坡为例,在现场勘查测绘、多期遥感数据分析、地表位移监测、室内试验测试及数值模拟分析的基础上,对滑坡的发育特征、活动特性、形成演化过程进行深入探讨,并对泻流坡滑坡滑源区潜在不稳定块体危险性预测进行科学评价。结果表明：(1)泻流坡滑坡为多因素耦合作用形成的大型高位堆积层滑坡,体积达188.35×10⁴ m³,可分为上部潜在滑源区、中部狭窄流通区、下部停淤堆积区3个区段,整体具有多期次、多层级、逐级后退式演化特征,各滑体滑动表现为蠕滑拉裂–推移式变形特点;(2)泻流坡滑坡的形成演化以活跃新构造运动为主导,易滑的孕灾地层为基础,差异性不协调地貌为条件,而降雨持续劣化、历史强震震裂效应及断裂蠕滑效应是滑坡失稳的主要诱发因素;(3)稳定性计算结果表明,目前滑坡整体处于基本稳定～欠稳定状态,在多个部位仍存在不同程度变形破坏,利用River-Flow^2D软件对上部潜在滑源区在极端降雨条件下启动和运动过程模拟结果显示,模拟最大滑动距离810 m,最大速度可达33.5 m/s,最大堆积厚度为26.7 m,总堆...     

三峡库区堆积层滑坡治理设计的可靠度分析

考虑滑带土抗剪强度指标的变异性,建立了三峡库区堆积层滑坡治理设计的可靠度分析方法。通过实例计算,分析了滑带土抗剪强度指标的概率分布特征对堆积层边坡稳定性的可靠度指标的影响。基于三峡库区50个堆积层滑坡治理工程案例,采用校准法,研究了堆积层滑坡治理设计的目标可靠度指标,得出一些初步结论。     

在水平和竖向地震加速度综合作用下的土壤滑坡

土工结构的传统设计方法是水平以地震作用系数的拟静力稳定分析为的基础的。本论文研究了以在水平和竖向加速度的综合作用下的稳定性和永久位移。采用的是对数螺旋线的破坏机理，试验结果表明，地震作用对斜坡的稳定性和永久位移有显著影响。对参数的研究表明如果相应的产加速度较大，别竖向加速度对稳定性和永久位移有重要影响。     

Complex landslide in the Rječina valley (Croatia): origin and sliding mechanism

This paper discusses the development of the Grohovo landslide on the north-eastern slope of the Rječina valley, the largest active landslide along the Croatian part of the Adriatic Sea coast. This complex retrogressive landslide was reactivated in December 1996. Thirteen separate slide bodies have been identified. The slide surface is considered to be on the upper flysch bedrock. Monitoring indicated that the magnitude of displacements was very different in time and space. The maximum movements were recorded on the upper part of the slope. The limestone mega-block and separated rocky blocks on top of the slope have also moved, which is not a typical phenomenon of the flysch slopes in the area of Rijeka.      

地震作用下钢筋混凝土框架结构中楼梯构件的影响效果分析

结合汶川地震中楼梯间的震害表现,根据楼梯的数量与布置方式以及主结构规模与布局构建了18个计算模型,对钢筋混凝土框架结构中楼梯构件的影响效果进行分析研究。结果表明:楼梯构件参与结构整体计算分析后,钢筋混凝土框架结构的侧向刚度、周期、振型、地震作用、层间位移、框架梁柱的地震内力等技术指标均有明显的变化,这种变化与楼梯构件的数量与布置方式以及主体结构的侧向刚度大小等因素密切相关。计算分析还表明,楼梯相关构件(斜板、平台梁、平台柱等)在地震作用下的受力非常复杂,结构设计时应对此有充分的考虑。     

Slope failures/landslides over a wide area in the 2018 Hokkaido Eastern Iburi earthquake

The 2018 Hokkaido Eastern Iburi Earthquake caused a large number of slope failures/landslides over a wide area. In particular, the enormous damage due to slope failures was centered in the towns of Atsuma and Abira which are located to the north of the epicenter. In Atsuma, a seismic intensity (Japan Meteorological Agency) of seven was observed. This was the first time an earthquake of such a large seismic intensity was recorded in Hokkaido, Japan. The geology in this region was mainly formed by three kinds of pyroclastic fall deposits (fa) due to the erupting of Mt. Tarumae, Mt. Eniwa and Shikotsu Caldera. The most serious damage was generated in these tephra stratus. In addition, the large-scale sliding of rock slopes composed of mudstone occurred in the Hidaka-Horonai River Basin in the Horonai district of Atsuma, and its debris flowed into the river and caused the blockage of the river channel. This paper summarizes the earthquake-induced damage to natural slopes, and presents the physical features and the mechanical properties of the collapsed pyroclastic fall deposits distributed over this area.     

Liquefaction in the Kanto region during the 2011 off the pacific coast of Tohoku earthquake

The present text is a summary of liquefaction events that occurred in the Kanto Region during the 2011 off the Pacific coast of Tohoku Earthquake, excluding those events in the Tokyo Bay area that are discussed elsewhere. Most liquefaction occurred in the abandoned river channels and former lakes that had been recently filled with liquefiable soils. Noteworthy was the damage to private housing lands and river dikes that had not been well treated against liquefaction risk. Many sites experienced repeated liquefaction after former earthquakes in 1923 or 1987, if they existed in those times. In contrast to the recent liquefaction-prone soils, more-aged sands scarcely liquefied because of what is called the “ageing” effect. The present study analyzed cases in Tokyo area to quantitatively assess the temporal development of ageing so that liquefaction risk in more aged soils might be reasonably assessed. In the appendix, remarks are made of the reliability of air-photo survey in quick detection of liquefaction sites.     

从剪切试验分析滑坡机理

通过制样并做饱和前后的剪切试验对比,测得其粘聚力及内摩擦角,结合土的力学性质,具体分析了滑坡发生的层面和机理,为更好更全面地预防滑坡、治理滑坡提供了可靠数据。     

填充墙在水平地震作用下的抗裂分析

对填充墙在水平地震力作用下的抗裂应力进行了分析,从理论上分析了填充墙开裂的控制因素,通过一系列的计算假定和理论计算,得出了填充墙在剪压共同作用下的抗剪强度是抗裂的主要控制因素,并求得该抗剪强度的计算公式。     

Analysis of landslide stability under seismic action and subsequent rainfall: a case study on the Ganjiazhai giant landslide along the Zhaotong-Qiaojia road during the 2014 Ludian earthquake,Yunnan, China

In a strong earthquake, not only a large number of coseismic landslides are triggered, but relaxation and cracks in the rocks and soils are induced, which make these rocks and soils vulnerable to instability during subsequent rainfall; thus, strong earthquakes always have long-term effects on landslides. The geo-hazards along the Zhaotong-Qiaojia road in the 2014 Ludian earthquake (Ms 6.5) of Yunnan Province, China, were investigated, and the Ganjiazhai giant landslide was chosen as a case study. First, using the limit equilibrium analysis and Newmark method, the critical seismic intensity of the landslide before the earthquake was evaluated. Secondly, the dynamic failure process of the landslide under the measured ground motion was simulated with the discontinuous deformation analysis method. Lastly, based on stress–seepage coupling analysis and precipitation data from Ludian meteorological station, the stability of the landslide during subsequent rainfall after the earthquake was predicted. The results show that the critical seismic intensity was within degrees VIII–IX, which is consistent with the results of the earthquake damage investigation. The dynamic failure process can be divided into four stages, and four scarps formed; the potential sliding zones during the subsequent rainfall were at the first scarp and the fourth scarp, and their critical rainfall amounts were 35–40 mm and 55–60 mm, respectively. In this paper, failure process simulation and stability prediction of the landslide before, during, and after the strong earthquake are presented, which provide analysis methods for the dynamic stability of landslides in the meizoseismal area.

     

地震诱发高速黄土滑坡的机理研究

针对１９２０ 年海原大地震（ Ｍｓ ＝ ８ ．５） ,１７１８ 年通渭大地震（ Ｍｓ ＝ ７ ．５） 和１６５４ 年天水大地震（ Ｍｓ ＝ ８ ．０） 等诱发的高速黄土滑坡所出现的种种现象与特征,提出了一种地震诱发高速黄土滑坡的机理---黄土体解体、斜抛和粉尘化效应。通过动力变形分析导出了黄土滑体斜抛运动的全过程及滑速、滑距公式。以海原大地震时,西吉县（１０°区） 回回川高速黄土滑坡为例,对这些公式进行验证,结果与实际情况相符。     

强震作用下某不稳定斜坡变形机制分析

"5. 12"汶川大地震发生后,在地震灾区发育了1 700余处"裂"而未"滑""松"而未"动"的震裂山体,这对地震灾区人民生命财产安全造成巨大危害。本文以四川省某不稳定斜坡这一典型震裂山体为研究对象,基于现场调绘-概念模型的建立-变形破坏机制及模拟验证的基本技术路线,通过野外大量的地质调绘工作为基础,全面地研究了边坡工程地质条件、坡体结构特征、岩土体结构特征以及边坡变形特征等,在此基础上,通过对该边坡地质过程发展演化特别是地震发生后斜坡体内出现的变形破坏迹象进行机制分析,建立了其变形破坏机制的概念模型。最后运用FLAC~(3D)程序对提出的概念模型进行数值模拟分析,验证了概念模型的正确性以及参数取值的合理性。     

地震作用下预制楼梯与框架结构相互作用分析

利用SATWE软件对无楼梯、现浇整体式楼梯及预制分离式楼梯三种方案的框架结构分别进行了振型分解法计算,对比分析了三种方案下结构的周期、水平地震作用、楼层位移及相邻框架柱的内力。分析结果表明,结构设计时应考虑楼梯作用;预制分离式楼梯具有比现浇整体式楼梯更合理的受力性能,对框架结构的影响相对较小。