澜沧江古水水电站坝址区上游左岸边坡双向差异卸荷特征及机理  

Bidirectional differential unloading characteristics and mechanism of the upstream left bank slope in dam site area of Gushui Hydropower Station on Lancang River

作　　者：唐豪 涂国祥[1] 张鑫 罗崎峰 TANG Hao;TU Guoxiang;ZHANG Xin;LUO Qifeng(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《水利水电快报》2023年第5期23-31,共9页Express Water Resources & Hydropower Information

基　　金：国家自然科学基金(41472274)。

摘　　要：为研究双向差异卸荷的特征及机理,以澜沧江古水水电站坝址区左岸上游岸坡为例,根据野外实地踏勘查明该边坡卸荷作用的强度,将岩层分为强卸荷区、弱卸荷区和原岩区3个区。统计并分析了研究区内各硐中卸荷裂隙的产状、张开度、张开裂隙率等现场实测数据,结果表明:由于澜沧江流向发生变化,从而产生双向差异卸荷现象,拐弯处两侧整体的卸荷作用强烈,这是澜沧江持续快速下切的结果。拐弯处上游侧岩层卸荷程度强于下游一侧,具体原因:①上游侧坡表与岩层走向相近,裂隙数量相对更多,贯通程度更好,对卸荷作用响应更剧烈;②上游侧岩体发生了倾倒变形,倾倒变形后的岩体结构更加松散破碎,反过来加剧了卸荷作用。In order to study the characteristics and mechanism of bidirectional,the upstream slope of the left bank of the GS hydropower station site area was studied as an example.According to the strength of the unloading effect identified by the field survey,the slope was divided into three zones:strong unloading zone,weak unloading zone and original rock zone.The measured data of the unloading fractures in the area,such as occurrence,opening degree and opening crack ratewere analyzed.The results showed that the phenomenon of differential unloadingin both directions was caused by the change of the flow direction of the Lancang River,and the unloading effect on both sides was strong as a result of the continuous and rapid down-cutting of the Lancang River.Because of the following reasons,the unloading of the upstream side of the bend was stronger than that of the downstream side:①the slope surface of the upstream side was close to the direction of the rock layer,and the original fissures were more numerous and had a better penetration,which responded more strongly to the unloading effect;②the rock body of the upstream side had been deformed by dumping,and the structure of the deformed rock body was more loose and broken,which aggravated the unloading effect in turn.

关 键 词：双向卸荷 谷坡卸荷 卸荷裂隙 古水水电站 澜沧江 

分 类 号：P642.2[天文地球—工程地质学]