滑坡堰塞坝坝体溃决机理与溃决实验研究综述

相对于人工土石坝,天然形成的滑坡堰塞坝缺少加固、防渗及泄洪等工程措施来稳定堰塞湖水位,坝体结构不稳定、基础资料缺乏,发生的溃决现象具有突发性强、几率高、危险性大、排险处理紧迫的特点,亟需深入系统的研究.作者结合国内外堰塞坝形成及其溃决问题的研究现状,介绍了滑坡堰塞坝与人工土石坝的溃决特性、滑坡堰塞坝的溃决模式及寿命特征,以及滑坡堰塞坝溃决特性的物理模型试验研究、原型观测及大比尺现场试验研究、梯级滑坡堰塞坝溃决特性试验研究进展.最后提出了关于堰塞坝溃决机理、堰塞湖处置、溃决模式、原型及模型试验比尺效应、溃决过程原型监测预警等方面建议的研究方向.     

Analysis of the Aso-Bridge landslide during the 2016 Kumamoto earthquakes in Japan

In 2016, earthquakes occurred beneath Kumamoto City, Kumamoto Prefecture in the Kyushu Region of Japan and generated numerous landslides around the city, and among those triggered in this disastrous event, the Aso-Bridge landslide was the largest. For the purpose of examining the behavior of this large-scale landslide during the main shock of the Kumamoto earthquakes, we conducted a study involving simplified sliding block concepts and finite element codes, and conclude that (a) the slope of the Aso-Bridge landslide (about 710 m high and with a dip angle of 33 °) is marginally stable in the absence of earthquakes; (b) the failure surface obtained using finite element codes is in satisfactory agreement with that of the actual failure surface; ©) our results reveal that the initiation-time of the Aso-Bridge landslide lay between 18.45 and 21 s based on three indications: (I) the directional tendency of the first apparent displacement, (ii) evidential factor of safety (FS) values <1, and (iii) Newmark’s displacement; and (d) the combination of an internal friction angle of 35 ° and a cohesion value of 80 kPa led to a failure surface closest to that observed in the field. The study demonstrates that we were able to apply the simplified sliding concepts and finite element codes to analyze the Aso-Bridge landslide in reasonable agreement with the actual event.     

Investigation of a loess-mudstone landslide and the induced structural damage in a high-speed railway tunnel

Bulletin of Engineering Geology and the Environment - This paper presents a landslide that occurred in loess hills resulting in structural damage to the Zhangjiazhuang tunnel of the...     

高土石坝地震安全控制标准与极限抗震能力研究

基于土石坝震害调查和原型观测资料分析，针对高土石坝的坝坡稳定、坝体地震永久变形以及混凝土面板接缝位移3个影响高土石坝安全的主要因素，初步建议了相应的地震安全控制标准，并应用于高心墙堆石坝和面板堆石坝的极限抗震能力计算分析。结果表明：按规范设计的高土石坝具有较强的抗震能力，其极限抗震能力在0.50g以上，可抵抗9度以上地震而不致于出现灾难性后果；高土石坝的极限抗震能力与相应的地震安全控制标准密切相关，按照本文建议的标准，高心墙堆石坝坝坡稳定是其极限抗震能力的控制因素，高面板堆石坝面板周边缝安全是其极限抗震能力的控制因素。     

堰塞坝漫顶溃决过程数值模拟及应用

堰塞坝作为自然形成的天然坝体,其结构不稳定性强,绝大多数的堰塞坝最终都将发生漫顶溃决,一旦溃决,将会对下游带来巨大的生命和财产损失。因此,有必要合理预测堰塞坝的溃决流量过程,为溃坝应急预案的编制提供理论与技术支撑。本文充分考虑堰塞坝的形态特征及坝料的物理力学特性,建立了一个可合理模拟堰塞坝漫顶溃坝过程的数学模型。该模型可较好地反映水动力条件下的溃口发展过程和下泄流量过程。选择西藏易贡堰塞坝溃坝案例对模型进行验证,通过计算结果与实测资料的对比发现:计算得到的溃口峰值流量、最终溃口宽度、峰值流量到达时间等参数的最大相对误差均在±15%以内;溃口流量过程与实测资料也吻合较好,有效地验证了模型的合理性;参数敏感性分析结果显示,残留坝高、冲蚀模式(单侧与两侧冲蚀)、冲蚀系数等参数对溃坝过程均有重要影响。     

平原多级储灰复合坝滑坡分析和加固治理

本文基于位于平原上的粉煤灰场二级复合储灰坝的二次滑坡过程,对土坝的勘察、论证、设计、加固的过程分析,提出对平原上的多级复合坝稳定分析的应力扩散的稳定验算,据此进行滑坡加固处理并经过蓄洪的考验获得成功,并大大地节省了治理的费用。     

地震作用下黄土滑坡加速度深度放大效应及震后变形模式研究

基于相似比理论,设计并完成了典型黄土滑坡物理模型试验,采用先进的离心机振动台技术,实现水平+垂直振动,研究黄土滑坡的地震动放大效应及变形模式,并配合有限差分数值模拟方法相互验证。结果表明：沿滑坡体浅表层加速度放大作用具有明显的趋表效应,水平向和垂向加速度放大效应呈非线性增加,且水平向大于垂向;在滑坡体的滑动面附近加速度放大作用呈现出岩性结构效应;随高程增加加速度响应逐渐增大,表现出高程效应,滑坡后壁放大作用明显。随入射地震波强度的增加,滑坡体内部关键部位加速度放大作用基本是先增大后减小的趋势。强震作用下黄土滑坡的破坏形式为：滑坡后壁形成拉裂隙并逐渐扩展,滑坡后壁发生崩塌,滑体略有下挫,形成拉槽,坡体中部鼓胀,坡脚有大量崩积物。研究结果为探讨地震作用下黄土滑坡的加速度放大效应和变形破坏情况,以期为天水地区黄土滑坡的地震稳定性评价和抗震设计提供参考。     

DNA-based stable isotope probing: a link between community structure and function

DNA-based molecular techniques permit the comprehensive determination of microbial diversity but generally do not reveal the relationship between the identity and the function of microorganisms. The first direct molecular technique to enable the linkage of phylogeny with function is DNA-based stable isotope probing (DNA-SIP). Applying this method first helped describe the utilization of simple compounds, such as methane, methanol or glucose and has since been used to detect microbial communities active in the utilization of a wide variety of compounds, including various xenobiotics. The principle of the method lies in providing ¹³C-labeled substrate to a microbial community and subsequent analyses of the ¹³C-DNA isolated from the community. Isopycnic centrifugation permits separating ¹³C-labeled DNA of organisms that utilized the substrate from ¹²C-DNA of the inactive majority. As the whole metagenome of active populations is isolated, its follow-up analysis provides successful taxonomic identification as well as the potential for functional gene analyses. Because of its power, DNA-SIP has become one of the leading techniques of microbial ecology research. But from other point of view, it is a labor-intensive method that requires careful attention to detail during each experimental step in order to avoid misinterpretation of results.     

地震应急避难场所疏散安置预案编制分析

地震应急避难场所是破坏性地震发生或地震预警信息发布之后,临时安置百姓生活的场所。5·12汶川8.0级地震、3·11东日本9.0级地震等国内外大量应急避难场所应用实例,充分证明了应急避难场所对于做好民众的疏散安置工作,稳定民心、安定社会,有着非常重要的作用。自2003年我国第一个应急避难场所——北京市朝阳区元大都城垣遗址公园应急避难场所建成以来,我国的地震应急避难场所规划建设工作得到全面发展。有关应急避难场所建设相关的法律、法规和标准相继出台,并不断完善。为使场所能够更好的服务于民众疏散安置工作,编制场所疏散安置预案是将场所设施功能与民众疏散安置工作有机结合的重要途径。该预案的编制对于规范     

连拱隧道-边坡耦合作用:连拱隧道滑坡

连拱隧道一般用于中、短隧道和隧道接线部位,除在隧道的进山、出山口遭遇仰坡和侧向边坡外,隧道主体也常处于边坡地形之中,需要对边坡的稳定性进行分析论证。连拱隧道开挖断面大,多次开挖支护以及应力的平衡、转换可能对边坡的稳定性产生显著影响,在极端不利情况下,甚至可能诱发滑坡。连拱隧道主体与边坡相互作用模式可概括为4种:隧道位于滑面以下;隧道穿越滑面;隧道位于滑面以上的坡顶;隧道位于滑面以上的坡脚,可采用修正的不平衡推力传递法分析其稳定性。对于边坡滑面不能预先判定情况,可采用数值计算方法,分析隧道开挖工法对边坡稳定性的影响。按强度折减法分析,在三导洞工法中先开挖远山侧更有利于边坡的稳定。     

Assessment and validation of GIS-based landslide susceptibility maps: a case study from Feltrino stream basin (Central Italy)

Landslide susceptibility studies focus on producing susceptibility maps starting from landslide inventories and considering the main conditioning factors. The validity of susceptibility maps must be verified in terms of model accuracy and prediction skills. This paper deals with a GIS-based landslide susceptibility analysis and relative validation in a hilly-coastal test-area in Adriatic Central Italy. The susceptibility analysis was performed via bivariate statistics using the Landslide-Index method and a detailed (field-based) landslide inventory. Selection and mapping of conditioning factors and landslide inventories was derived from detail geomorphological analyses of the study area. The susceptibility map was validated using recent (shallow) landslides in terms of both model accuracy and prediction skills, via Success rate and Prediction rate curves, respectively. In addition, a pre-existing official landslide inventory was applied to the model to test whether it can be used when a detailed (field-based) inventory is not available, thereby extending its usability in similar physiographic regions. The outcome of this study reveals that slope and lithology are the main conditioning factor of landslides, but also highlights the key role of surficial deposits in susceptibility assessment, for both their type and thickness. The validation results show the effectiveness of the susceptibility model in both model accuracy and prediction skills given the good percentage of correctly classified landslides. Moreover, comparison of the susceptibility map with the official Regional landslides inventory proves the possibility of using the developed susceptibility model also in the absence of detailed landslide mapping, by considering inventories that are already available.     

Risk factors for casualty in earthquakes: The application of epidemiologic principles to structural engineering

Past investigations of the public health consequences of natural disasters, such as earthquakes, have generally suffered from a lack of comprehensive data due, in part, to the difficulty faced in mounting a significant data collection effort in the aftermath of such an event. This lack of meaningful data severely hampers the ability of casualty researchers to develop reliable and robust estimates of death and injury in future events; these numbers are critical in planning for mitigation and response activities. The basic data required as input to these models are risk factors for injury which can only effectively be estimated through a careful epidemiologic study of those injured (and not injured) in past events. This paper outlines the field of earthquake injury epidemiology and discusses the application of the collected data. An example of a recent case-control study (in progress) is given. Implications for the broader application of these techniques to structural engineering are suggested.     

Evaluation of dynamic stability and analysis of reinforcement measures of a landslide under seismic action: a case study on the Yanyangcun landslide

Bulletin of Engineering Geology and the Environment - Earthquakes are a major landslide trigger, and evaluation of the dynamic stability of landslides under seismic action is very important. The...     

拾珠揀玉 承前启后

由北京土木建筑学会、北京城建技协古建园林组、北京市东城区土木建筑学会、北京市第二房屋修缮工程公司五个单位联合筹办的《古建园林技术》期刊,终于和广大读者见面了。这是古建园林事业中一件很有意义的工作,是从事这一工作的同志们十分需要与欢迎的。     

Housing policy – the link between welfare and economic development

Many Western European countriesturned into welfare states in the 1950s, wherebyhousing became a tool of income redistribution,largely through the construction of a largesubsidized rental stock. In Northwestern Europe,over 60 percent of the present stock was built after1945. The states' response to housing shortages wasgeared to increasing social equity; a huge financialeffort was needed to accommodate the rapidly growingnumber of households. Since the early 1970s,governments have been trying to increase theeconomic efficiency of their housing systems withoutcompromising social equity. Consequently, the focusof housing policy shifted from blanket regulation totargeted support for households in need. Morefundamental changes lie ahead, as governments nowgive priority to economic development goals. Thisarticle outlines the role that housing policy canplay in Europe's economic development. Whereashousing policy generally follows the economy, thatlink could also work the other way around. As localgovernments compete for economic growth, a promisingstrategy is to improve local housing conditions.     

Formation and evolution of a successive landslide dam by the erosion of river: a case study of the Gendakan landslide dam on the Lancang River,China

Bulletin of Engineering Geology and the Environment - A landslide dam located on the Lancang River in Southwest China was used as a case to study the landslide formation and evolution process...     

双城记:神户地震和马尔马拉地震的经济影响

灾害的影响也取决于各个城市的发展水平和灾害准备水平.这一点显著的证明是日本神户(1995年遭受里氏7.2级地震)与土耳其马尔马拉(1999年遭受里氏7.4级地震)的实例对比.     

某滑坡稳定性分析与评价

以花栗树包滑坡Ⅲ的工程实践为例,通过整理相关勘查资料、岩土试验等资料,分析了该滑坡的基本情况、滑坡体的物质组成、结构特征及物理力学性质,探讨了滑坡的破坏机理,用极限平衡法对滑坡体的稳定性进行了计算,并对其在不同工况条件下的稳定性进行了分析、评价与预测。     

Exploring spatial non-stationarity in the relationships between landslide susceptibility and conditioning factors: a local modeling approach using geographically weighted regression

Landslide susceptibility is the likelihood of landslide occurrence, in a specific place and time. The identification of the potential relationships between landslide susceptibility and conditioning factors is very important towards landslide hazard mitigation. In this paper, we implement a local statistical analysis model geographically weighted regression, in two catchment areas located in northern Peloponnese, Greece. For this purpose, we examined the following eight conditioning factors: elevation, slope, aspect, lithology, land cover, proximity to the drainage network, proximity to the road network, and proximity to faults. Moreover, the relationship between these factors and landsliding in the study area is examined. The local statistical analysis model was also evaluated by finding its differences with the performance of a standard global statistical model logistic regression. The results indicated that the global statistical model can be enhanced by the application of a local model. The outputs of the proposed approach favored a better understanding of the factors influencing landslide occurrence and may be beneficial to local authorities and decision-makers dealing with the mitigation of landslide hazard.

     

Calculation of landslide danger and maximum landslide pressure by the variation method

The authors give a calculation of soil pressure carried out at Giprorechtrans by the RUST computer program, and compare it with analogous calculations by the SL VAR program, which was described in a previous issue of our journal. “Giprorechtrans” joint-stock company. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, pp. 31–32, March–April, 1994.