张家口地区地壳稳定性研究

发布时间：2018-04-02 08:30

  本文选题：张家口地区　切入点：地壳稳定性评价与分区　出处：《中国地质科学院》2017年博士论文

【摘要】：张家口是京津冀协同发展规划建设的重要地区,近年来重大工程基础设施建设发展迅速。张家口地区位于张家口-渤海活动构造带的西北段,活动断裂发育、地震频发、现今地应力高,开展该区地壳稳定性评价研究具有重要的理论意义和实用价值。本文依据地壳稳定性评价理论和研究思路,以构造稳定性为主,突出构造演化规律、活动断裂、现今构造应力场、地震危险性在地壳稳定性评价过程中的作用,配合岩土体结构及特征和外动力地质灾害研究,进行综合评价和分区,取得了以下主要结论和认识:1、张家口地区白垩纪以来至少经历了七个重要的构造活动阶段:①白垩纪早期快速隆升;②白垩纪晚期-古新世宁静稳定的剥蚀期;③古新世晚期-渐新世早期喜马拉雅运动I幕;④渐新世早期-渐新世晚期宁静稳定的剥蚀期;⑤渐新世晚期-中新世早期喜马拉雅运动II幕;⑥中新世晚期宁静稳定的剥蚀期;⑦上新世晚期喜马拉雅运动Ⅲ幕。张家口地区晚第四纪以来继承了新构造运动的特征,虽然活动强度较新构造时期有所减弱,但地壳运动仍以垂直运动为主,处于相对活跃阶段。2、张家口地区活动断裂以NW-NWW向和NE-NEE向活动断裂为主,并控制了一系列晚新生代沉积盆地。NE-NEE向活动断裂主要以正断活动为主,NW-NWW向活动断裂具有明显的正断兼左旋走滑特征。NE-NEE向断裂由晚中生代强烈的挤压逆冲转变为上新世以来正断活动,记录了华北地区中-新生代区域性挤压、伸展以及岩石圈垮塌构造演化过程,揭示了张家口地区由晚中生代东亚大陆多向汇聚体系转变为新近纪以来印度和欧亚板块碰撞引发的软流圈的东扩张效应和太平洋俯冲带的跃迁式东撤的联合效应这一过程。3、张家口地区水平主应力值随深度的增加近似呈线性增加的趋势,最大水平主应力随深度线性增加的梯度为0.0706MPa/m,最小水平主应力随深度线性增加的梯度为0.0384MPa/m,主应力关系表现为SHShSv,水平主应力起主导作用,且具有很高的地应力值。最大水平主应力方位为N25°～86°E,平均方位为N59°E,有利于区域内NW-NWW向断裂产生左旋走滑活动,同时利于NE-NEE向断裂的正断/右旋走滑活动。4、张家口地区岩土体工程地质类型以变质岩、岩浆岩为主,沉积岩主要分布于研究区南部。岩土体可划分为四个工程区,分别为坚硬岩组工程区、较坚硬岩组工程区、较软弱岩组工程区、软弱岩组工程区,根据不同岩组的结构特征、岩性组合以及力学性质特征进一步划可分为坚硬块状侵入岩组、坚硬厚层-块状变质岩、坚硬块状火山岩岩组、坚硬中厚碳酸盐岩组、较坚硬火山岩组、较坚硬碳酸盐岩组、较坚硬碎屑岩组、较软质碎屑岩组、软质碎屑岩组九个亚区。5、张家口地区地质灾害以泥石流为主,主要分布在基岩山区及山区与盆地交接部位,崩塌、滑坡主要分布在基岩山区、沟谷岸坡及人类工程切坡强烈的地区,并且滑坡灾害规模较小、数量少。崩塌、滑坡、泥石流的形成主要受地形地貌、岩性、地质构造以及降雨影响,其中降雨是主要诱发因素。6、张家口地区地壳稳定性分析以构造稳定性为主,配合岩土体稳定性和地面稳定性分析,进行张家口地区和崇礼冬奥会场区两个层次的综合评价和分区研究。张家口地区整体以稳定和次稳定区为主,少量次不稳定或不稳定区,不稳定区主要分布于延矾盆地北缘和怀涿盆地北缘,应为京张高铁重点设防地段;崇礼冬奥会场区地壳稳定性为稳定和次稳定级,具有很好的地质安全保障,为2022年冬奥会规划建设提供了地质科技支撑。
[Abstract]:Zhangjiakou is an important area of Beijing Tianjin Hebei collaborative development plan, in recent years the rapid development of basic facilities construction of major projects. Zhangjiakou area is located in the northwest section of Zhangjiakou - Bohai tectonic zone, active faults, earthquake prone, high in-situ stress, and has important theoretical significance and practical value to carry out research on shell stability evaluation in this area in this paper. On the basis of crustal stability evaluation theory and research method, the structural stability, prominent tectonic evolution, fault, tectonic stress field, the seismic risk evaluation function in the process of crustal stability, with rock and soil structure and characteristics and dynamic geological disaster research, comprehensive evaluation and zoning, made the following main conclusions: 1, the Zhangjiakou area since the Cretaceous period experienced at least seven important tectonic stages: Early Cretaceous uplift; The late Cretaceous Paleocene quiet stable denudation; the late Paleocene to early Oligocene Himalaya movement I; the early Oligocene - Late Oligocene quiet stable denudation; the late Oligocene to early Miocene Himalaya movement II; late Miocene in the quiet stable period of erosion; the Pliocene the late Himalaya Movement III scene. The Zhangjiakou area since the late Quaternary inherited the characteristics of neotectonic movement, although the activity intensity is in new tectonic period has weakened, but still in the vertical movement of crustal movement, in a relatively active period.2, active faults in Zhangjiakou area with NW-NWW and NE-NEE trending active faults, and a series of control the late Cenozoic sedimentary basin.NE-NEE to active faults mainly in normal faulting, NW-NWW to active fault has obvious positive fault and strike slip characteristics of.NE-NEE to break by night Generation of intense extrusion rushed into reverse since Pliocene normal faulting, recorded in North China Cenozoic regional extensional collapse and extrusion, Lithosphere Tectonic Evolution, reveals the combined effect of Zhangjiakou area change from Late Mesozoic continental East Asia system for multi direction convergence of asthenosphere since Neogene India and Eurasia collision caused the expansion piece effect and the Pacific subduction zone transition type eastward the process of.3, the Zhangjiakou area increased horizontal principal stresses with depth increases linearly approximate gradient, maximum horizontal principal stress increases linearly with depth is 0.0706MPa/m, minimum horizontal principal stress gradient with depth increases linearly as 0.0384MPa/m and the main stress in relation to SHShSv, horizontal stress plays a dominant role, and has a very high stress. The maximum horizontal principal stress range is N25 to 86 DEG E, average range Is N59 ~ E, the region NW-NWW faults produce sinistral strike slip activities, at the same time to NE-NEE trending normal faults / dextral slip.4, geological types of geotechnical engineering in Zhangjiakou magmatite, metamorphic rocks, sedimentary rocks are mainly distributed in the south of the study area. The rock soil body can be divided into four a construction zone, respectively for the hard rock group project area, a hard rock group project area, relatively weak rock group construction zone, soft rock group project area, according to the structure characteristics of different rocks, lithology and mechanical properties further planning can be divided into hard lump intrusive rock group, thick and hard - rock block hard lump, volcano rock, hard thick carbonate group, hard rock volcano group, hard carbonate group, hard clastic formation, soft clastic formation, soft clastic rock group nine sub district.5, Zhangjiakou geological disasters in debris flows, Mainly distributed in the Rocky Mountains and the junction of mountain and basin, collapse, landslide is mainly distributed in the Rocky Mountains, valley slope and human engineering area strong cut slope, landslide and the number of smaller, less collapse, landslide, debris flow formation is mainly controlled by lithology, topography, geological structure and rainfall, the rainfall is the main predisposing factors for.6 analysis to the structural stability as the crustal stability of the Zhangjiakou area, with the analysis of the stability of rock mass and ground stability, Zhangjiakou area and Chongli Olympic venue two comprehensive evaluation and zoning of time. Zhangjiakou region as a whole in a stable and stable region, a small amount of time is not stable or unstable area. The unstable region is mainly distributed in the northern margin of the northern extension of Huailai Zhuolu basin and alum basin, should be the Beijing Zhangjiakou High-speed Rail key protection area; crustal stability in Chongli area. The Winter Olympics venue The stable and secondary stability level, with good geological security guarantee, provides geological science and technology support for the 2022 Winter Olympic Games planning and construction.

【学位授予单位】：中国地质科学院
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P542;P642
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本文编号：1699573