重力式锚碇水平极限承载力估值公式探讨  

Exploration on the Horizontal Limit Bearing Capacity Formula of Gravity Anchorage

作　　者：尹小涛[1] 严飞 周磊[1] 王东英[1] 邓琴[1] YIN Xiao -tao YAN Fei ZHOU Lei WANG Dong -ying DENG Qin(State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, China National Engineering Laboratory for Surface Transportation Weather Impacts Prevention, Yunnan Provincial Plan Design and Research Institute of Communications, Kunming, Yunnan 650041, China)

机构地区：[1]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试验室,武汉430071 [2]云南省交通规划设计研究院陆地交通气象灾害防治技术国家工程实验室,昆明650041

出　　处：《铁道工程学报》2017年第1期41-46,共6页Journal of Railway Engineering Society

基　　金：云南省交通科技项目〔云交科2011(LH)12-a;云交科2014(A)01〕;陆地交通气象灾害防治技术国家工程实验室开放基金(NELBP201501)

摘　　要：研究目的:当前基于摩擦设计的重力式锚碇的水平极限承载力估值偏保守,没有考虑锚碇结构与地基协同作用,联合承载的估值结果与实际偏差较大。本文利用平硐岩基摩擦试验、重力式锚碇基底深部位移监测和数值仿真试验等手段,探讨重力式锚碇与岩基的协同作用和联合承载机制。研究结论:(1)极限试验破坏形态揭示了重力式锚碇不是单纯的摩擦承载,而是锚-岩联合承载;(2)锚碇-岩基联合极限承载分为两个阶段和三个效应,初期为基底摩擦极限承载,摩擦效应;之后,前部齿坎夹持岩体剪切破坏极限承载,锚岩系统联合承载性能达到极限,夹持效应;基底上覆土重量对上述两部分都有提高,回填效应;(3)提出了考虑上述效应和联合承载机制的重力式锚碇水平极限承载力估算公式,经工程案例检验,公式极限估值9.6P与数值仿真确定的极限值8.0P接近,说明公式精度有保证,符合实际破坏模式;(4)该研究成果可用于新型重力式锚碇的设计和安全监控领域。Research purposes： Horizontal limit bearing capacity under current design of gravity anchorage based on friction design condition is often conservatively estimated. The estimated value without consideration of synergy and joint bearing mechanism of gravity anchorage and base is greatly deviated from practical one. Using friction test of rock base in adit, monitoring section of deep displacement under base bottom and numerical simulation experiment, the synergy and joint bearing mechanism of gravity anchorage and base is discussed in the paper. Research conclusions： （1） Fail mode presented by limit test proves that gravity anchorage is not friction bearing, but anchorage and base joint bearing. （2） The limit bearing capacity of anchorage ＆ rock base can be divided into two stages and contains three effects, first being friction effect supported by friction limit bearing capacity of anchorage base bottom, second is clamping effect presented by clamping rock mass shearing limit capacity, third is buried depth effect enhanced the former two limit bearing parts by refilling soil weight on base and structure. （3） The estimation formula for horizontal limit bearing capacity of gravity anchorage with above three effects considered is built, which is checked by project ease, limit result of formula being 9.6P is close to that of numerical test being 8.0P, these prove precision of the formula and conform to practical fail mode. （4） The achievement above can be used in design and monitoring fields of new type gravity anchorage.

关 键 词：重力式锚碇 协同作用 联合承载机制 水平极限承载力估算公式 

分 类 号：TU457[建筑科学—岩土工程]