Geometrical and Geotechnical Characteristics of Landslides in Korea under Various Geological Conditions

The goal of this study is to determine the geometrical and geotechnical characteristics of landslides under various geological conditions using detailed field surveys, laboratory soil tests and precipitation records. Three study areas are selected to consider different rocks, including gneiss in Jangheung, granite in Sangju and sedimentary rocks in Pohang, South Korea. Many landslides have occurred in these three areas during the rainy season.Precipitation records indicate that landslides occurring in the gneiss area of Jangheung and granite area of Sangju may be influenced by the hourly rainfall intensity rather than cumulative rainfall.However, landslides occurring in the sedimentary rock area of Pohang may be influenced by hourly rainfall intensity and cumulative rainfall. To investigate the factors that influence these types of landslides, a detailed landslide survey was performed and a series of laboratory soil tests were conducted.According to the detailed field survey, most landslides occurred on the flanks of mountain slopes, and the slope inclination where they occurred mostly ranged from 26 to 30 degrees, regardless of the geological conditions. The landslide in the gneiss area of Jangheung is larger than the landslides in the granite area of Sangju and sedimentary rock area of Pohang.Particularly, the landslide in the sedimentary rock area is shorter and shallower than the landslides in the gneiss and granite areas. Thus, the shape and size of the landslide are clearly related to the geological conditions. According to the integrated soil property and landslide occurrence analyses results, the average dry unit weight of the soils from the landslide sites is smaller than that of the soils obtained from the nonlandslide site. The average coefficient of permeability of soils obtained from the landslide sites is greater than that of soils obtained from the non-landslide sites with the same geology. These results indicate that the soils from the landslide sites are more poorly graded or looser than the soils from the non-landslide sites.

An overview of the resources and environment conditions and major geological problems in the Yangtze River economic zone, China

Focusing on the Yangtze River economic zone,the previous geological researches are systematically summarized,resources and environment conditions and major geological problems which are needing to be concerned in land planning and construction are studied.The results show that the resource conditions of cultivated land,shale gas,geotherm,lithium and so on are superior in the Yangtze River economic zone,and the resources and environment conditions are conducive to develop the modern agriculture,clean energy industry and strategic emerging industries.3×1013 m^2 farmlands without heavy metal pollution are concentrated;there are three national level shale gas exploration and development bases with explored reserves of 5.441×1011 m^3;geothermal availability is 2.4×109 t of standard coal each year,equivalent to 19% of the amount of coal in 2014;Asia's largest energy lithium metal ore deposit is found.In some parts of Yangtze River economic zone,there are some major geological problems such as active faults,karst collapse,ground subsidence,landslide-collapse-debris flow,affecting the river-crossing channels,high-speed railway,urban agglomeration and green ecological corridor planning and construction.Those problems should be concerned,and the relevant suggestions and countermeasures are put forward.Meanwhile,the ideas to further support the development of the Yangtze River economic zone are put forward.

河南省泌阳县崩滑流灾害孕灾地质条件分析

为分析泌阳县地质灾害孕育、形成的地质环境条件,深化地质灾害早期识别、形成机理和规律认识,在地质灾害风险调查成果的基础上,分别对崩塌、滑坡、泥石流进行孕灾地质条件分析。针对地形地貌、地质构造、工程地质岩组、斜坡结构、水文地质条件、人类工程活动等孕灾因子进行分析。研究结果表明,崩塌、滑坡主要孕灾因子为地形地貌、工程地质岩组及斜坡结构;泥石流主要孕灾因子为地形地貌和工程地质岩组。结合主要孕灾因子,将全县划分为四个孕灾大区及若干小区,并对各分区孕灾地质条件进行详细论述,阐明不同分区内主要孕灾因素。

不同降雨工况条件下的崩滑地质灾害危险性评价

为针对性地采取预防、避让、治理等地质灾害防治与管控提供依据,完善在地质灾害危险性评价中将降雨作为单一诱发因子参与评价体系的弊端,在大雨、暴雨、大暴雨和特大暴雨4种不同降雨工况条件下进行了研究区崩滑地质灾害危险性评价。以云南省元阳县作为研究区域,以栅格单元作为评价单元,选取地貌类型、高程、坡度、坡向、曲率、工程地质岩组、土地利用类型、断层距离和河流距离9个评价因子,采用主观的层次分析法与客观的信息量模型相结合的加权信息量模型对元阳县崩塌、滑坡进行了地质灾害易发性评价。研究结果表明:基于自然间断点法元阳县域可分为低、中、高、极高4类易发区,4类易发区面积分别占元阳县面积的21.55%,35.46%,25.53%和17.16%。利用ROC曲线得出区划结果精度AUC值为0.812,表明区划结果很好。在易发性评价基础上,以年平均最大日降雨量为诱发因素,分别对大雨、暴雨、大暴雨和特大暴雨4种工况条件下的研究区进行了崩塌、滑坡地质灾害危险性评价,得到了大雨([25,50) mm)工况、暴雨([50,100) mm)工况、大暴雨([100,250]mm)工况和特大暴雨(>250 mm)工况4种条件下基于极值假设的研究区崩滑地质灾害危险性评价结果,并对不同降雨工况条件下的地质灾害危险性评价结果进行了对比分析,确定了地质灾害危险性评价结果在不同降雨条件下的空间合理性。通过与实际调查结果的对比表明,4种不同降雨工况条件下的崩滑地质灾害危险性评价结果与实际高度吻合,说明评价结果具有较高的可靠性与合理性。

黔东北地区地质灾害时空分布规律及孕灾地质环境研究

黔东北地区是一个地质环境复杂的地区,地质灾害分布范围广、数量多,属于贵州省地质灾害高易发区域。为了深入研究地质灾害时空分布特征与孕灾地质环境规律,以黔东北地区沿河县为研究区,通过野外孕灾地质条件实地调查成果资料,结合历年地质灾害数据,详细阐述研究区内地质灾害分布的总体特征,总结地质灾害孕灾地质条件,深入分析各类孕灾因子对滑坡、崩塌等地质灾害发育的控制作用,通过综合分析研究区内孕灾地质条件,进一步将研究区划分为三大孕灾地质条件区,为减轻地质灾害风险、防灾减灾提供了科学依据。研究结果表明:研究区内地质灾害发生的时间受月平均降雨量影响十分显著;空间分布情况受地层岩性特征影响较大;区内地质灾害主要孕灾地质条件为地形地貌、地层岩性、斜坡结构等,降雨和人类工程活动为外部诱发因素;区内易滑地层主要为中志留统秀山组、下志留统龙马溪组、下奥陶统大湾组等;易崩地层主要为下奥陶统大湾组、下志留统雷家屯组、中二叠统茅口组;不同灾种的斜坡结构具有明显的差异性,滑坡主要发育于凹型和折线型斜坡,崩塌则多发育于凸型斜坡;研究区内地表水系与地质灾害发生具有一定关联性,区内乌江流域水系沿线200m范围内发生地质灾害数量占灾害总数的9.74%。

不同天然海绵体特征条件下的海绵城市建设适宜性研究

海绵城市建设是近年来城市规划和雨洪管理的重要方向。针对不同的地质环境条件特征,海绵城市建设的适宜性和措施建议各不相同。本文通过对郑州市白沙和高新两个典型地貌单元的海绵城市建设示范区进行研究,在查明区域地质环境条件的基础上,运用层次分析法对两个示范区的天然地质海绵体的适宜性进行评价。评价指标选取地表海绵体中的土地利用现状、地表岩性、地形坡度、土壤环境质量,地下海绵体中的岩性结构组合、厚度。评价结果显示白沙示范区适宜性整体优于高新示范区一个级别。白沙示范区浅层地下水埋深较浅,地层渗透性强,若加大开采力度,其海绵城市建设的蓄水能力会大大增强,海绵城市建设的适宜性也会随之提升;高新示范区虽水位埋藏深,但地层渗透性差,海绵城市建设潜力相对较小。针对不同的天然海绵体条件特征,应辅以相应的LID设施建议。

基于GIS的崩滑地质灾害孕灾地质条件分析——以西藏嘉黎县为例

嘉黎县内构造作用强烈,地势陡峭,地质环境条件较差,加之2018—2022年修建国道G349对原有地形的破坏,使得县域内地质灾害数量剧增,每逢汛期或遇强降雨天气,区内地质灾害频发。通过收集嘉黎县2018—2023年地质灾害资料,结合野外实地调查,基于GIS平台对县域内的地质灾害发育分布情况和孕灾地质条件进行详细分析。孕灾地质条件的分析主要选取地形地貌、地质构造、地层岩性、土地利用类型和人类工程活动等因素,选取的孕灾因子有高程、坡度、剖面曲率、断层密度、水系密度、工程地质岩组、土地利用类型和距公路距离。分析结果表明:县域内最主要的孕灾地质条件为人类工程活动、地形地貌、地质构造、工程地质岩组、土地利用类型等。结合县域内各孕灾地质条件特征分成5个孕灾分区,并详细阐述各个分区内地质灾害分布发育规律和孕灾地质条件特征。通过对嘉黎县的孕灾地质条件分析,有利于认识地质灾害的发育规律,建立健全地质灾害防治和风险管控体系,为地质灾害防治管理和国土空间规划提供基础依据。

贵州凤冈南北向隔槽式褶皱变形区滑坡孕灾地质条件研究

贵州凤冈南北向隔槽式褶皱变形区独特的地质构造形成了典型的侏罗山式褶皱组合区,其与滑坡的孕育具有较强的关联性。本研究基于实地调查与数据分析,通过地质构造、地形地貌、地层岩性及河流分布等因素与滑坡发育的关系,探讨研究区滑坡孕灾地质条件。结果表明,研究区滑坡主要发育于构造相互截接严重的区域;在地形上主要发育于高差100300 m、坡度25°35°的顺向坡和斜向坡,地貌类型以侵蚀—溶蚀沟谷地貌为主;滑坡孕育地层具有倾向性,主要为志留系兰多维列统韩家店组(S1h)的泥岩、页岩及奥陶系中下统湄潭组(O1-2m)的页岩、砂质页岩;研究区河流对斜坡的影响范围平均为900 m,影响区内距河流越远,滑坡发育数量越少。

从路线穿越巨型古滑坡谈山区公路地质选线

山区公路中,复杂地形、地貌、工程地质条件、场地环境等极大的影响着公路线位确定。以蒙象路为依托,基于白石巨型古滑坡两阶段勘察成果,以地质选线作为主要手段对项目白石古滑坡路段进行两阶段方案比选,包含线位工程地质条件、路基与桥梁的工程类型适应性等内容,最终采用在初设E线方案基础上优化后的A线方案,在项目已施工完成通车情况下验证了前期地质选线实践的合理性,进而引伸出山区公路地质选线综合性要点。公路地质选线应以地形、地质条件为基础进行综合性选线及精细化选线,产生最优解以确定最终路线方案;对于选线中遇到大型不良地质体情况,应查明其规模、性质等,合理评价其现状和实施工程建设后的整体及分区稳定性,有条件时可谨慎通过,必要时应采用适宜的工程措施。

滑坡防治措施的总体分析及实例应用研究

为切实掌握滑坡灾害的防治措施,该文结合滑坡工程实际,首先对滑坡灾害防治措施进行总体分析,再进一步进行了实例应用研究。分析结果表明:滑坡防治措施主要包括减轻或消除水威胁、设置抗滑措施及土体改善措施,且结合工程实际,本文实例的防治措施设计为“抗滑桩+挡土墙+截排水措施”。

探究水工环地质条件对矿山开采的影响

采矿工作复杂程度极高,需要结合矿山开采工作实际需求,做好矿山水工环地质勘查工作,了解和掌握水工环地质条件,才能最大程度的确保矿山安全开采。本文结合实践,探论分析采矿工作实际受水工环地质带来的影响,以期为相关人士提供一些借鉴和参考。

A new method for spatio-temporal prediction of rainfall-induced landslide

Geological condition and rainfall are two most principal conditions inducing landslides in the Chongqing region. By analyzing the forming conditions of rainfall-induced landslides, a new method for spatio-temporal prediction of rainfall-induced landslide is brought forward on the basis of grading and overlapping geological condition and rainfall factor in this paper. At first, semi-quantitative assessment and grading for the geological condition of a certain area or slope can be carried out with the multi-factor interactive matrix. Then the severity of rainfall in that area is grading according to the maximum daily rainfall and the total rainfall in a rainfall course. Finally, the “landslide probability judgement factor” can be worked out through grading and overlapping “geological condition influenc- ing factor” and “rainfall influencing factor”, by which the landslide can be graded into 4 grades, they are landslide extremely easily happening, landslide easily happening, landslide difficultly happening and landslide hardly ever happening respectively. More accurate spatio-temporal prediction of rain- fall-induced landslides can come true on the ground of detailed geological survey of some dangerous slopes in an area and more precise weather forecast. Finally, the reliability and feasibility of carrying out the spatio-temporal prediction of rainfall-induced landslides with the method of “two factors” grading and overlapping are validated by the example of Jipazi landslide.

From the new Austrian tunneling method to the geoengineering condition evaluation and dynamic controlling method

The new Austrian tunneling method （NATM） is widely applied in design and construction of underground engineering projects. When the type and distribution of unfavorable geological bodies （UGBs） associated with their influences on geoengineering are complicated or unfortunately are overlooked, we should pay more attentions to internal features of rocks grades IV and V （even in local but mostly controlling zones）. With increasing attentions to the characteristics, mechanism and influences of engineering construction-triggered geohazards, it is crucial to fully understand the disturbance of these geohazards on project construction. A reasonable determination method in construction procedure, i.e. the shape of working face, the type of engineering support and the choice of feasible procedure, should be considered in order to mitigate the construction-triggered geohazards. Due to their high sensitivity to groundwater and in-situ stress, various UGBs exhibit hysteretic nature and failure modes. To give a complete understanding on the internal causes, the emphasis on advanced comprehensive geological forecasting and overall reinforcement treatment is therefore of more practical significance. Compre- hensive evaluation of influential factors, identification of UGB, and measures of discontinuity dynamic controlling comprises the geoengineering condition evaluation and dynamic controlling method. In a case of a cut slope, the variations of UGBs and the impacts of key environmental factors are presented, where more severe construction-triggered geohazards emerged in construction stage than those predicted in design and field investigation stages. As a result, the weight ratios of different influential factors with respect to field investigation, design and construction are obtained.

祁雨沟公峪金矿开采技术条件及水力联系研究

为了给祁雨沟公峪金矿进一步勘探开发提供依据,有效保护矿山地质环境,促进矿业经济持续、健康发展,研究了祁雨沟公峪金矿水文、工程、环境地质条件。研究得出,矿区位于区域地下水径流、排泄区,含水层主要有3类,水文地质条件总体较简单,受含水层透水性影响,矿区地下水与地表水联系联系微弱;根据矿区内各类岩土体工程地质特征,将其划分为4类工程地质岩组,大部分区域表层岩土体风化强烈,较为破碎,但深部岩体完整性较好,工程地质条件较好,矿区范围内地层分布稳定、承载力高,有利于主副井工程辅助设施的建设;研究区仅发现1处地面塌陷,没有发生较大的崩塌、滑坡、泥石流、地裂缝等自然地质灾害,矿山环境地质条件复杂程度分级为中等。结合矿区地形地貌、工程地质、水文地质、环境地质条件,评估区其他区地质灾害危险性小,评估区采矿活动对含水层影响程度较轻。研究表明,矿床复杂程度的综合类型为二类一型,属开采技术条件简单的矿床。

贵州省长顺县滑坡与崩塌灾害的孕灾地质条件分析

长顺县地质灾害隐患点多面广,主要由滑坡与崩塌组成,具有隐蔽性、突发性、破坏性和动态变化等特点。以长顺县108处代表性地质灾害点为研究对象,探讨分析了地形地貌、工程地质岩组与水文地质条件等对地质灾害的影响。研究表明:滑坡主要集中发生在坡度为10°~30°,相对高差为20~50 m的土质斜坡上,滑坡灾害的发生与降雨具有较明显的正相关性;崩塌主要分布在坡度≥60°,相对高差为50~150 m的硬质岩斜坡。根据长顺县地质灾害发育特征,结合工程地质条件可将全区的孕灾地质条件划分为易孕灾区、较易孕灾区与一般孕灾区。

西南山区高速铁路主要工程地质问题研究

高速铁路具有沉降控制要求严格、速度快、运营安全舒适的特点,但西南山区地形高差显著、板块活动强烈、构造岩性复杂、气候极端恶劣,其特殊复杂的地质环境孕育了危岩落石、采空区、高地应力、基底上拱、巨型岩溶、隧道涌水突泥、非煤有害气体、隧道运营地质灾害等众多工程地质问题,制约着高速铁路向西南山区的延伸。本文对西南山区建成或在建的8条高速铁路干线主要工程地质问题的经验进行了总结,系统梳理了尚未解决或亟待优化的难点或痛点,分析了各类问题存在的原因,探寻了解决方案和研究思路,以期为广大高速铁路工程技术人员提供创新发展的方向。

宣汉县滑坡地质灾害孕灾地质条件分析

滑坡地质灾害是宣汉县发育最广泛、影响最大的灾种,严重威胁人民群众的生命财产安全。通过资料收集、野外调查与综合研究,对宣汉县滑坡地质灾害的发育特征与孕灾地质条件进行分析与研究。结果表明:宣汉县滑坡地质灾害发育时空特征明显,且与地貌类型、坡度、地形起伏度、工程地质岩组、距断裂距离以及斜坡结构等密切相关。

乌什县崩塌地质灾害发育特征与影响因素研究

区内由于兴建道路削坡、降雨、地震或冰雪融化等因素,导致崩塌地质灾害的发生,造成人员伤亡和经济财产损失。经调查分析,乌什县崩塌灾害多发育在坚硬-较坚硬的层状碳酸盐岩地层上,处于45°~88°之间的陡崖及陡坡区域。在地震、降水、植被覆盖率降低等自然环境条件影响下,加快了崩塌地质灾害的发生。其中,人类工程活动的不合理开发、建设是诱发崩塌地质灾害发生的重要影响因素之一。通过对乌什县崩塌地质灾害发育特征和影响因素的研究,可为当地防灾减灾、崩塌地质灾害防治提供科学依据。

黔东南黄平县地质灾害发育特征与孕灾环境条件分析

归纳总结黔东南黄平县地质灾害发育特征和分布规律,分析孕灾环境条件及主要孕灾因子权重,对地质灾害孕育、形成的环境条件进行分区,并有针对性地提出防控措施建议。结果表明,地质灾害的形成、发生与所处的环境条件密切相关,地形地貌、地层岩性和地质构造为主要的内在诱发因素,降雨则是主要的外部诱发因素,人类工程活动也是重要影响因素;将研究区划分为高、中和低孕灾区三个等级,其面积占比分别为23.2%、13.6%和63.2%。以期为该区地质灾害防治工作提供依据。

基于县域详查的黎平县地质灾害孕灾地质条件分析

黎平县地质灾害主要为滑坡和崩塌。以贵州省黎平县地质灾害详细调查和风险评价资料为基础,通过实地进行地质调查和室内综合分析研究,从地形地貌(坡高、坡度、坡型)、地层岩性、工程地质岩组和斜坡结构等孕灾地质条件对贵州省黎平县滑坡和崩塌数据进行分析,县内主要以青白口系浅变余砂岩、砂质板岩、板岩为主,地质灾害发育趋势以上孕灾地质条件分布总体明显,主要发育在坡高30~100 m,坡度30°~70°,直线型和凸形坡,青白口系清水江组Pt_(3)^(1d)q、平略组Pt_(3)^(1d)p浅变质软质岩中,所得结论符合客观事实,对贵州省黎平县乃至黔东南浅变质岩地区研究地质灾害孕灾地质条件、地质灾害防治、地质灾害风险管控有较好参考价值,对其他孕灾地质条件与黎平县相似的地区有一定的启示。