固化粉土抗拉特性试验研究  

Research on Tensile Characteristics of Stabilized Silt

作　　者：谭敏[1] 朱志铎[1] 

机构地区：[1]东南大学岩土工程馆,南京210096

出　　处：《地下空间与工程学报》2013年第S2期1811-1816,共6页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金项目(40872173);江苏交通科技项目

摘　　要：通过劈裂抗拉试验,研究了3类固化剂固化粉土劈裂抗拉强度随龄期、固化剂种类和掺量的变化规律,分析了固化粉土劈裂破坏时的破坏形态及破坏机理。研究结果表明:3类固化剂固化粉土的劈裂抗拉强度随着龄期的增长而增加,劈裂抗拉强度与龄期具有幂函数关系;新型固化剂固化粉土的抗拉性能较另外2类固化剂固化粉土具有明显优势;随着掺量的增加,新型固化剂固化粉土的抗拉强度增加明显。在加载初期,固化粉土试样表面未有裂缝出现,随着荷载的增大,其表面开始出现裂缝;新型固化剂固化粉土劈裂裂缝最初引发时间长,开裂荷载和极限荷载的时间间隔也较长。固化粉土发生劈裂破坏时,3类固化剂固化粉土裂缝开展的宽度和深度不一,劈裂破坏形式不同。石灰-粉煤灰、石灰-粉煤灰-水泥固化粉土试样破坏为脆性破坏,新型固化剂固化粉土试样破坏时并非人们所认为的拉伸破坏。Through split tensile test on 3 kinds of silt-stabilizer,the tensile strength of the silt changed with age,types and content of stabilizer has been studied,as well as the failure mode and failure mechanism of stabilized silt.Research results show that the split tensile strength of 3 types of solidified soil increases with the age. The regression analysis showed that,there was a good correlation between split tensile strength and age. Split tensile strength of stabilized-silt of new stabilizer was higher than that of other 2 kinds of stabilized-silt. As the addition increases,the tensile strength of stabilized-silt by new stabilizer increases significantly. At the preliminary stage of loading,no cracks were found on the surface of the sample,as the load increases,cracks began to emerge on its surface,but splitting crack was originally raised at various time interval. New stabilizer stabilized-silt split crack was originally raised with the longest time interval,between loads of cracking and ultimate loads there was long time interval. For the solidified soil specimen with 3 curing agents,when splitting failure occurs,cracks have different width and depth,splitting failure is of various configurations. Lime-fly-ash,lime-fly ash-cement-stabilized silts have brittle failure,and the stabilized-silt by new stabilizer has failure not the tensile one as current theory considered.

关 键 词：固化粉土 劈裂抗拉强度 裂缝 破坏形态 破坏机理 

分 类 号：TU411[建筑科学—岩土工程]