摘要
随着我国“西电东送”特高压电网的全面铺开,大量输电杆塔坐落在滑坡灾害易发的滇东北山区,这类山坡的稳定性直接关系着输电线网的安全稳定运行。然而,目前的研究尚未明晰输电杆塔修建对降雨型滑坡灾害的影响,需要进一步研究杆塔荷载和降雨特征耦合作用下的边坡稳定性变化趋势。基于Geo Studio模型,以西南山区输电线路典型边坡为例,从土壤含水率、孔隙水压力、边坡安全系数和土体位移等方面定量分析降雨强度、降雨历时、杆塔荷载大小及荷载组合等因素对边坡稳定性的影响机理。结果显示:(1)对于以超渗产流机制为主的滇东北红土边坡,降雨历时的延长、总降雨量的增加对边坡安全系数的削弱效应强于降雨强度的提高;(2)杆塔荷载对边坡稳定性的削弱效应明显,增加单个杆塔荷载的大小将大大提高滑坡发生的可能性,在长历时暴雨-入渗条件下杆塔失稳风险显著增加;(3)杆塔荷载的存在会延长近地表土体正孔隙水压力消散的时间,进而延长边坡欠稳定状态历时;(4)调整杆塔荷载组合的大小会对边坡整体稳定性产生不同影响:增大下坡段杆塔荷载重量,边坡整体稳定性提高,增大上坡段杆塔荷载重量,边坡整体稳定性降低。研究表明杆塔荷载在长历时暴雨条件下会提高输电线路途经山坡滑坡灾害的发生概率和破坏性,不合理的杆塔组合也会导致边坡向欠稳定甚至失稳状态发展,在输电线路滑坡灾害防治工作中需引起重视。本研究可为滇东北山区输电线路规划、运维及防灾减灾工作提供科学指导。
With the fast development of China′s Ultra-High Voltage power grid,a large number of transmission towers are located in the mountainous areas of northeast Yunnan,where landslide disasters are prone to occur.The stability of such slopes is directly related to the safe and stable operation of the transmission line networks.However,the current research has not yet clarified the impact of transmission tower construction on rainfall-induced landslide disasters,and it is necessary to further study the change trend of slope stability under the coupling effect of tower load and rainfall characteristics.Based on the Geo Studio model,taking the typical slope of transmission line area in the northeast Yunnan province as an example,the influence mechanisms of rainfall intensity,rainfall duration,tower load and load combination on slope stability were quantitatively analyzed from the aspects of soil moisture content,pore water pressure,slope safety factor and soil displacement.The result show that:(1)For the laterite slope in northeastern Yunnan,which was dominated by the mechanism of infiltration excess runoff,the weakening effect of the increasing rainfall duration and total rainfall amount on the slope safety factor was stronger than that of increasing rainfall intensity.(2)The weakening effect of increasing tower load on slope stability was obvious.Increasing the load of a single tower could greatly increase the possibility of landslide,and the risk of tower instability would increase significantly under the condition of long-term rainstorm-infiltration processes.(3)The existence of tower load prolonged the dissipation time of the positive pore water pressure of the near-surface soil and then prolonged the duration of the unstable state of the slope.(4)Adjusting the load combination of transmission towers could have different result on the overall stability of the slope:increasing the load weight of the tower on the lower slope section,the overall stability of the slope could be improved,while increasing the load weight of the tower on the upper slope section,the increase of downward load pressure would lead to further reduction of the overall stability of the slope.The research shows that the tower load will increase the probability and destructiveness of the landslide disaster along the transmission line under the condition of long-term rainstorm.Unscientific tower combinations will also lead to the transition of hillslope stability from less-stable state to unstable state,which should be paid attention to in the prevention and control practices of the landslide disasters along transmission lines.This study provided scientific guidance for transmission line planning,operation and maintenance,and disaster prevention works in mountainous areas of northeast Yunnan.
作者
赵鹏
张辉
禹聪
王维
李庆东
柴灿
曾庆尧
王开正
唐鸿磊
ZHAO Peng;ZHANG Hui;YU Cong;WANG Wei;LI Qingdong;CHAI Can;ZENG Qingyao;WANG Kaizheng;TANG Honglei(Zhaotong Bureau of Power Supply of Yunnan Power Grid Co.,Ltd.,Zhaotong 657000,Yunnan,China;Kunming University of Science and Technology School of Electric Power Engineering,Kunming 650500,Yunnan,China)
出处
《水利水电技术（中英文）》
北大核心
2024年第S01期350-363,共14页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(52107017)
云南电网有限责任公司2022年应用研究类科技项目(YNKJXM20220112)
中国水利水电科学研究院实验室开放基金(IWHR-SKL-KF202220)
