新疆乌尉高速天山段岩石冻融破坏特征及崩塌模式分析

发布时间：2018-03-12 11:40

本文选题：乌尉高速天山段　切入点：岩石冻融　出处：《成都理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：乌尉高速天山段以近南北向横切东天山，属于高寒高海拔地区，区内地层岩性复杂，且属天山构造带，经历了多期的复杂褶皱、断裂、抬升等运动，形成如今的构造格局。路线沿途经历山前洪积平原、高山峡谷、山间盆地、河谷阶地等多种地貌单元，并切割不同的岩土体，加上研究区特有的大温差气候条件，形成了边坡地质灾害的多样性。本文通过现场深入调查，系统收集了乌尉高速天山段具有典型高寒高海拔地区的岩体冻融及边坡崩塌灾害的地质信息，对沿线91个边坡崩塌灾害进行分析与评价，探索了区内岩体冻融风化对边坡稳定性的影响以及区内崩塌边坡的破坏机制。在此基础上，选取典型崩塌灾害点，结合室内试验及数值模拟等方法，分析了研究线路上崩塌灾害的成灾机制，失稳模式及发展规律。通过以上研究，论文主要成果如下：（1）研究区跨越多种地貌单元，其中天山北坡主要为横向峡谷及盆地宽谷区，而南坡则多为宽谷区。地层岩性复杂，路线走廊带分布了自元古界～古生界～中生界～新生界的地层以及花岗岩体。气候多样，本地区一年中最大温差达到70℃，昼夜最大温差也可达40-50℃，降雨主要集中在6-8月，且4、5月时天气较暖，开始雪融、河流解冻。（2）研究发现，乌尉高速天山段岩石冻融主要受以下因素影响：①气候因素，提供冻融风化所需的大温差及水分；②岩性条件，岩石的胶结程度越好，抗冻融风化能力越强；③结构面条件，结构面是冻融风化的通道，增大了裂隙，提供了更多的临空面，加速了冻融风化；④地应力因素，地应力影响了岩体内裂隙的扩展以及裂隙水的赋存范围，从而影响了岩石的冻融风化；⑤岩体的物理性质是影响冻融特性的主要因素，密度小、孔隙率大、含水量高的岩石受冻融循环影响显著，反之，含水量小的岩石受冻融循环影响较小；⑥冻融温度范围越大周期越长则冻融风化越强烈；⑦岩石热力学性质，在一定程度上影响着岩体温度的变化以及大温差的范围，，从而影响了冻融风化的速度。（3）天山北坡线路边坡高陡，崩塌灾害发育程度比南坡高，且主要集中在海拔2200m以上的高寒高海拔山区。按照崩塌灾害的失稳模式分类，可把区内崩塌分为冻融—风化剥落、滑塌、倾倒、坠落四种模式；其中，冻融—风化剥落为研究路线上典型的失稳模式，主要分布在胜利达坂附近2500m以上的路段。而其余三种典型失稳模式，在研究区段内均有分布，且滑塌失稳的数量最多，研究揭示这一现象源于区内边坡岩体的卸荷裂隙（沟谷与区域最大主应力方向垂直）、构造裂隙与冻融劈裂频繁的耦合作用。（4）从对典型冻融崩塌边坡的数值模拟可以看出，①温度越低，冻融时间越长，循环次数越多，则边坡的冻融越强烈，其冻融深度也随之逐步加深。②随着温度的降低，冻融循环的次数的增多，岩体所受剪应力越来越大（一般呈线性关系增长），边坡被破坏的速度越快。③在冻融作用中，边坡首先从外层临空面开始被破坏，并随着冻融的进行，岩体逐层剥落并最终形成崩塌。
[Abstract]:Wu Wei high-speed section of East Tianshan Tianshan nearly north-south cross, belong to the alpine high altitude area, strata complex lithology, and Tianshan Belt, has experienced complicated folds, multi fracture, uplift movement, tectonic form today. Along the route through the alluvial plains, mountains and valleys and mountain basin. Terraces and other landforms units, and cutting rock and soil in different climatic conditions, large temperature difference and the study area characteristic, forming a diversity of slope geological disasters.
Through field investigation, geological information system collects Wu Wei high-speed rock Tianshan section has typical Alpine high altitude and slope freeze-thaw collapse, analysis and evaluation on the 91 landslide disasters, exploration in the area of rock freeze-thaw weathering effect on slope stability and failure mechanism of the landslide slope area. On this basis, the typical landslide disasters, combined with laboratory experiment and numerical simulation methods, analyzes the disaster mechanism research on the line collapse, instability and the law of development.
Through the above research, the main achievements of this paper are as follows:
(1) the study area a variety of landforms, the northern slope of the Tianshan Mountains is mainly horizontal gully area and valley basin, the southern slope of gully region. It is a complex lithology, corridor route distribution from the Proterozoic to Paleozoic Mesozoic Cenozoic strata ~ ~ and granite. Climate diversity, local year maximum the temperature reached 70 degrees, the maximum temperature difference between day and night is up to 40-50 DEG C, rainfall mainly concentrated in 6-8 months, and 4,5 months when the weather is warmer, the snow melt rivers began, thawing.
(2) the study found, mainly by the following factors of Wu Wei high-speed Tianshan section of rock freeze-thaw: climatic factors, with large temperature difference and water freeze thaw weathering required; the lithology and rock cementation degree, freeze-thaw weathering ability is strong; the structure of surface structure, surface is frozen weathered channel, increase the fissures, provide more free surface, accelerated freeze-thaw weathering; the stress factors, the effects of stress of rock fracture expansion and fissure water in scope, thus affecting the freeze-thaw and weathering of rock; the rock physical properties are the main factors, the influence of freeze-thaw characteristics low density, high porosity, high water content of rock freeze-thaw cycle significantly, whereas small water content of rock freeze-thaw cycle is smaller; the freeze-thaw temperature range the greater the longer the cycle of freeze-thaw weathering rock and thermodynamics of more intense; Quality affects the temperature change of rock mass and the range of the large temperature difference to a certain extent, thus affecting the speed of the weathering of the freeze-thaw.
(3) on the northern slope of Tianshan Mountains line of high steep slope, landslide disaster development than the south, and mainly concentrated in the above 2200m Alpine high altitude mountain. According to the classification of collapse disaster loss of stability in the region, can be divided into freeze-thaw collapse - weathering, collapse, collapse, falling four models; the freeze thaw weathering - loss, steady mode as the research route of the typical, mainly distributed in the victory over 2500m Road near Osaka. While the rest of the three typical failure modes, were distributed in the study region and slide instability of the largest number of studies reveal this phenomenon originates from the area of rock slope the unloading fissure (maximum principal stress direction of Regional Gully and vertical), structural cracks and freeze-thaw coupling frequently.
(4) from that of typical numerical simulation of freezing thawing slope collapse, the lower the temperature is, the longer the time of freeze-thaw cycles, more freeze-thaw slope is more intense, the freezing thawing depth gradually deepened. Second, with the decrease of temperature, increase the times of freezing and thawing cycles, rock mass the shear stress increasing (general linear growth), slope destruction faster. In the freezing and thawing, first from the outer surface of slope has been destroyed, and with freezing and thawing, rock layer peeling and eventually collapse.

【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U418.55;P642.21

【参考文献】