摘要
针对水分诱发边坡失稳和传统边坡排水技术效率低的问题,结合真空负压、袖阀注浆和锚固技术,研发一种新型真空锚管,阐述其构成、工作机理和技术优势。基于排水固结理论,给出考虑真空负压作用的锚管周围土体孔隙水压力和抗剪强度计算式。探讨真空锚管拉拔受力性能与破坏形式,推导出考虑真空排水固结效应的锚管抗拔承载力计算公式。开展室内真空锚管排水-拉拔试验,探究真空锚管工作特性,并与理论计算对比。结果表明:试验测得的孔隙水压和拉拔承载力与理论值吻合较好,证明提出真空锚管具有良好的排水和锚固特性,给出的理论分析方法有效;负压作用能有效降低锚管周围土体的孔隙水压力和含水率,提升土体抗剪强度和锚管抗拔承载力;真空锚管承载力-位移曲线可分为弹性、非线性塑性扩展和塑性贯通3个阶段;锚管总承载力等于各扩体承载力之和;可为水分诱发滑坡治理提供新技术和理论依据。
Aiming at the moisture-induced slope instability and low efficiency of traditional slope drainage technology,combined with vacuum negative pressure,sleeve valve grouting and anchoring technology,a new type of vacuum anchor pipe was developed,and its composition,mechanism and technical advantages were described.Based on the drainage consolidation theory,the calculation formulas of pore water pressure and shear strength of soil around the anchor pipe considering the effect of vacuum negative pressure were given.Based on the discussions on the pullout stress characteristics and failure modes of the vacuum anchor pipe,the calculation formulas of pullout bearing capacity considering the vacuum drainage consolidation effect were deduced.The indoor drainage pull-out test of the vacuum anchor pipe was carried out to explore the working characteristics of the vacuum anchor pipe and compare with the theoretical calculation.The results show that the measured pore water pressure and pull-out capacity in the test are in good agreement with the theoretical calculation values,proving the good drainage and anchoring characteristics of the vacuum anchor pipe,and the effective theoretical analysis method given.The negative pressure can effectively reduce the pore water pressure and water content of the soil around the anchor pipe,while improve the shear strength of the soil and the pull-out capacity of the anchor pipe.The bearing capacity and displacement curve of the vacuum anchor pipe can be divided into three stages of elastic,nonlinear plastic expansion and plastic penetration.The total bearing capacity of anchor pipe is equal to the sum of each expansion body force.It provides a new technical and theoretical basis for the treatment of water induced landslide.
作者
董旭光
李峥
崔自治
李宏波
王永胜
DONG Xuguang;LI Zheng;CUI Zizhi;LI Hongbo;WANG Yongsheng(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2022年第12期114-124,共11页
Journal of the China Railway Society
基金
国家自然科学基金(51968061)
宁夏回族自治区重点研发计划(2021BEG03023)
宁夏大学贺兰山学者青年项目(2017067)
宁夏大学西部一流大学和一流学科项目(NXYLXK2021A03)。
关键词
真空锚管
工作机理
排水固结
承载特性
排水-拉拔试验
vacuum anchor
working mechanism
drainage consolidation
bearing characteristics
drainage and pullout test
