川西松潘黄土发育特征与工程地质力学特性分析

发布时间：2018-06-30 20:56

本文选题：青藏高原 + 原位直剪　；参考：《地质力学学报》2017年05期

【摘要】：以松潘幅和漳腊幅1∶5万工程地质调查为基础,通过野外地质调查、地质测年、地理空间分析、室内试验和大型原位直剪试验等工作手段,对松潘黄土的发育分布特征和工程地质力学特性进行研究分析,认为松潘黄土具有以下特性:(1)松潘黄土为风成黄土,局部地形的变化通过控制近地面气流的运动从而影响松潘黄土的堆积,使得松潘黄土的分布与研究区地形、地貌的变化联系密切;(2)松潘黄土粉砂含量大于80%,大多含有碎石,碎石物质成分主要以砂板岩、炭质板岩和石英为主;(3)研究区内的松潘黄土主要分布于2712~3437 m的高程范围内,在山体南坡的分布远多于北坡,在地形开阔的断陷盆地内,黄土发育厚度大且呈广泛连续式分布,在高深的峡谷区,黄土的发育厚度变化大且呈零星的片状分布;(4)松潘黄土结构性明显,其力学性质受物质成分、含水率和天然结构面的影响,具有中等—强的湿陷性,黄土的结构性、水敏性、湿陷性等性质是该套地层内地质灾害发育的主要因素,松潘黄土的不良工程地质特性严重影响着研究区内未来重大工程的规划建设。
[Abstract]:Based on the 1: 50 000 engineering geological survey of Songpanzhuang and Zhanglaguan, and through field geological surveys, geological dating, geospatial analysis, laboratory tests and large in-situ direct shear tests, etc. The development and distribution characteristics of Songpan loess and the engineering geological and mechanical properties are studied and analyzed. It is concluded that the Songpan loess has the following characteristics: (1) Songpan loess is an aeolian loess. The variation of local topography affects the accumulation of Songpan loess by controlling the movement of air flow near the ground, which makes the distribution of Songpan loess closely related to the topography and geomorphology change in the study area. (2) the silt content of Songpan loess is more than 80, most of which contain gravel. Sand slate, carbonaceous slate and quartz are the main components of gravel. (3) the Songpan loess in the study area mainly distributes in the elevation range of 2712 ~ 3437 m, the distribution in the south slope of the mountain body is much more than that in the north slope, and in the faulted basin with open topography, the rock mass is mainly composed of sand slate, carbonaceous slate and quartz. The thickness of loess is large and distributed in a wide continuous pattern. In the deep canyon region, the developed thickness of loess varies greatly and is distributed sporadically. (4) the structure of Songpan loess is obvious, and its mechanical properties are affected by material composition. The influence of water content and natural structural plane is of moderate to strong collapsibility. The properties of loess, such as structure, water sensitivity and collapsibility, are the main factors for the development of geological disasters in this set of strata. The bad engineering geological characteristics of Songpan loess seriously affect the planning and construction of future major projects in the study area.
【作者单位】：中国地质科学院地质力学研究所;国土资源部新构造运动与地质灾害重点实验室;中国地质大学(北京)地球科学与资源学院;
【基金】：中国地质调查局项目(DD20160271) 国家自然科学基金项目(41402321)
【分类号】：P642.131;TU444

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