土-岩组合地基变截面锚杆承载性能与机制研究  

Bearing behavior and mechanism of variable-section anchors in soil-rock composite foundation

作　　者：曾二贤 程述一 伍林伟 陈成[3] 吏垚 刘观仕[3] ZENG Er-xian;CHENG Shu-yi;WU Lin-wei;CHEN Cheng;LI Yao;LIU Guan-shi(Central Southern China Electric Power Design Institute of CPECC,Wuhan,Hubei 430071,China;State Grid Corporation of China,Beijing 100031,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)

机构地区：[1]中国电力工程顾问集团中南电力设计院有限公司,湖北武汉430071 [2]国家电网公司,北京100031 [3]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《岩土力学》2024年第7期2117-2128,共12页Rock and Soil Mechanics

基　　金：国家电网有限公司科技项目(No.SGZB0000TGJS2300369);中电工程中南电力设计院科技项目(No.QQ02231);国家自然科学基金(No.41972293)。

摘　　要：以山区输电线路工程为背景,针对实践中广泛遇到的上土下岩二元层状地基,提出了一种变截面锚杆技术,其原理为通过增大上覆土层中锚杆的截面积,达到充分利用上覆土层和下部岩层承载力的目的。为检验变截面锚杆的性能,采用现场真型试验和数值模拟相结合的手段,探讨了其承载力提升机制,分析了不同因素对承载特性的影响规律。研究表明,较等截面锚杆,变截面锚杆的上拔、下压以及水平承载力均有所提升。其中,水平承载性能提升效果最显著。场地覆土层厚度对锚杆上拔承载力影响较大,对下压和水平承载性能影响较小。场地地形坡度对锚杆水平承载性能有较大影响,二者呈负相关。此外,“上拔荷载+水平荷载”模式下,变截面群锚基础的承载性能优于等截面群锚基础和传统复合基础,且具有土方开挖量小以及更适用于斜坡地形的优点。研究成果可为该新型基础的推广应用提供技术支撑。A type of variable cross-section anchor is proposed for the binary layered foundation with upper soil and lower rock that is widely encountered in transmission line engineering.Its principle is to increase the cross-sectional area of the anchor in the overlying soil layer to fully utilize the bearing capacity of the soil and rock.To examine the performance of the proposed anchor,the load-bearing capacity improvement mechanism of the variable cross-section anchor is discussed through a combination of field tests and numerical simulations,and the effect of different factors on the bearing performance is investigated.The results indicated that compared with uniform section anchor,the uplift,downward,and horizontal bearing capacities of the variable cross-section anchor are increased,and the horizontal bearing performance is improved significantly.The thickness of covering soil on the sites has a significant impact on the uplift bearing capacity of the anchor,while the influence on the downward and horizontal bearing capacity is less.The terrain slope of site has a great influence on the horizontal load-bearing performance of the anchor,and the two are negatively correlated.Furthermore,under the“uplift+horizontal”loading,the group anchor foundation with variable cross-section anchor exhibits higher bearing capacity than the one with uniform section anchor and the traditional composite foundation,and also has the advantages of small excavation volume and more suitable for slope terrain.This study can provide technical support for the application of this new type of foundation.

关 键 词：输电线路 杆塔基础 岩石锚杆 土-岩组合地基 数值分析 

分 类 号：TU431[建筑科学—岩土工程]