Abstract: Debonding?of?interface?between?steel?strand?and?grout?is?the?dominant?failure?model?of?conventional?prestressed?anchor?cable,?and?in?order?to?avoid?the?debonding,?the?bulb?anchor?of?structural?engineering?is?modified?appropriately?and?used?in?geotechnical?anchorage?engineering?to?enhance?the?anchorage?capacity?of?embedment?section.?Eight.cement-based?grouts?with?different?mixing?ratios?are?designed,?in?which?bulb?and?conventional?anchor?cables?are?embedded?in?mediumweathered?sandstone.?Then?the?complete?load-displacement?curves?of?the?rock?anchors?are?obtained?by?pull-out?tests?in?laboratory.?The?test?results?indicate?that?load-transfer?mechanism?of?conventional?anchor?and?bulb?anchor?is?different?obviously?due?to?wedging?effect?of?bulb?structure,?the?bearing?strength?of?bulb?anchor?is?markedly?higher?than?that?of?conventional?an-?chor,?and?the?bulb?structure?decreases?the?sensibility?of?bearing?strength?of?rock?cable?bolt?to?embedment?length?and?mechanical?performance?of?cement-based?grout.?These?characteristics?of?bulb?anchor?can?elevate?the?utility?efficiency?of?cable?materials,decrease?the?amount?of?anchors,reduce?the?project?costs?and?enhance?the?safe?reliability?of?anchorage?system.?So?it?is?worthy?of?applying?bulb?anchor?popularly?to?the?actual?engineering.

Key words: geotechnical anchorage , bulb anchor , conventional anchor , pull-out test , bearing strength

摘要： 普通预应力锚索的常见破坏模式是钢绞线与注浆体脱黏,为防止该类破坏模式的发生并增强内锚固段的锚 固能力,将结构工程中的压花锚引入到岩土锚固工程中并进行较大改进,设计8种不同配合比的水泥基注浆体,将 压花锚、普通锚锚固在中风化砂岩中,通过抗拔试验获得岩锚的荷载??位移全过程曲线。结果表明:压花结构在注浆 体里产生楔形效应,导致压花锚的荷载传递机理与普通锚不同,其承载强度显著高于对应的普通锚,降低了岩锚承 载强度对内锚固段长度及注浆体力学性能改变的敏感性。压花锚的上述特性有利于提高锚固工程筋材的利用效 率,减少用锚数量,降低工程造价,增强锚固系统的安全可靠度。

关键词: 岩土锚固, 压花锚, 普通锚, 抗拔试验, 承载强度