摘要
基于青藏高速公路某隧道出口溜砂坡的现场勘察、测试及室内试验,通过工程地质分析与相似模型试验,对该溜砂坡的发育特征、影响因素、形成机理进行了探讨,并提出了防治对策。结果表明:该溜砂坡为大型砂粒、碎屑牵引式中强活动溜砂坡;不同颗粒比重条件下溜砂坡的影响因素主要包括含水率、冻融、地震力、工程活动等方面,中砂的天然休止角小于粗砂、砾砂等粗颗粒,含水率与砂粒的天然休止角呈正相关,在含水率达到10%以后影响效果减弱,冻融作用对粗颗粒的休止角影响较大,当含水率达到一定条件后,冻融作用才开始凸显,当含水率增大到一定程度时,冻融对休止角的影响呈减弱趋势,地震力作用在低含水率条件下,作用显著,随着含水率的增加,效果减弱;将溜砂坡划分出了砂源区、溜动区、堆积区三个分区,从力学、运动学角度分析了该溜砂坡的形成、运动与复活全过程;提出了砂源区控制+固砂+排砂综合防护对策。
The development characteristics,influencing factors and formation mechanism of the sand-sliding slope were discussed based on the site survey,testing and laboratory tests of the sand-sliding slope at the exit of a tunnel on the Qinghai-Tibet Highway,through engineering geological analysis and similar model tests,and then prevention and control strategy were proposed.The results show:The sand-sliding slope is a large-sized sand and debris-dragging medium-strong active sand-sliding slope;Influencing factors under different particle specific gravity conditions include moisture content,freezing and thawing,seismic forces,and engineering activities.The natural angle of repose in sand is smaller than that of coarse sand,gravel,etc.The moisture content is positively correlated with the natural angle of repose of the sand,and the effect is reduced after the moisture content reaches 10%.Freeze-thaw effects have a great influence on the angle of repose of coarse particles.When the moisture content reaches a certain condition,the freeze-thaw effect begins to become prominent.When the moisture content increases to a certain extent,the influence of freezing and thawing on the angle of repose tends to decrease.Seismic force acts at a low moisture content and has a significant effect.As the moisture content increases,the effect decreases.The sand-sliding slope was divided into three zones:the sand source zone,the slip zone and the accumulation zone.The whole process of formation,movement and resuscitation of the sand-sliding slope was analyzed from the perspective of mechanics and kinematics.The comprehensive protection measures of sand source area control,sand consolidation and sand discharge are put forward.
作者
邢军
王建斌
XING Jun;WANG Jianbin(The Xi’an China Highway Geotechnical Engineering Co.,Ltd,Xi’an,Shaanxi 710075,China)
出处
《中国地质灾害与防治学报》
CSCD
2019年第2期1-8,共8页
The Chinese Journal of Geological Hazard and Control
基金
高寒高海拔地区道路工程安全与健康国家重点实验室自主创新基金项目(ZC20170511)
关键词
青藏高速
溜砂坡
形成机理
模型试验
Qinghai-Tibet Expressway
sand-sliding slope
development mechanism
model test
作者简介
第一作者:邢军(1980-),男,内蒙古人,高级工程师,主要从事高速公路勘察设计及科研工作。E-mail:57496139@qq.com
