摘要
在我国的西北地区,强烈冻融、风蚀等对性质脆弱的土建筑遗址安全构成极大威胁。研究了冻融循环对土遗址耐久性的影响。选择新疆交河故城原状生土试样和重塑土试样进行了冻融循环试验,监测冻融过程中的质量变化,并在冻融循环结束后进行了风洞试验和强度试验。冻融试验结果表明,在试样初始含水率较低的情况下,前5个冻融循环,试样经历了一个质量增大的过程;在随后的冻融过程中伴随着冻干和吸湿,原状试样质量的整体趋势是减小的,重塑样质量的变化趋势维持水平。随冻融循环次数增大,原状试样的微结构出现损伤,强度减小,风蚀量增大,即耐久性持续变差。相反,冻融循环初期,重塑样的强度有所增大,风蚀量减小,耐久性得到了提高;随着冻融循环的增加,重塑样的强度开始下降。重塑试样由于重塑过程中其结构受到破坏,强度弱化,冻融循环引起重塑土的"陈化",愈合了土体的结构,但随着冻融进行,矿物颗粒的微结构损伤不断增大,试样的耐久性降低。
Earthen architecture ruins is mostly found in the arid area, which suffers from strong wind erosion, freeze-thaw process. Influence of cyclic freezing-thawing on the durability of earthen architecture are researched. Cyclic freezing-thawing are conducted on the undisturbed and remolded specimens from Jiaohe cultural heritage, Xinjiang, China to understand the durability of earthen architecture to wind erosion and the strength attenuation. Test results show, under low original water content, the undisturbed and remolded specimens masses are increased during the beginning five freezing-thawing cycles. With the change of moisture content during the freezing and thawing process, undisturbed specimen weight expresses a decreasing tendency; and remolded specimens weight maintains a level of weight. With the increasing of freezing-thawing cycles, undisturbed specimens show a decrease in compressive strength and an increase in wind erosion quantity due to microstructure damage; that is, a weakening in durability. However, the remolded specimens exhibit an enhancement of microstructures at beginning cycles, characterized by an increase in strength and a decrease in wind erosion, that is, an improvement in durability. It is considered the healing effect of destroyed mierostrueture and the aging of chemical cohesive agents are responsible for the strengthening of remolded specimen at the earlier freezing-thawing cycles. At the further freezing-thawing cycles, the remolded specimens turn to exhibit a decreasing tendency on durability following the increasing damage of microstructure.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2011年第8期2267-2273,共7页
Rock and Soil Mechanics
基金
国家科技支撑计划课题资助项目(No.2006BAK30B02)
关键词
土建筑遗址
冻融循环
风蚀
耐久性
earthen architecture ruins
cyclic freezing and thawing
wind erosion
durability
作者简介
严耿升，男，1983年生，博士研究生，主要从事环境岩土工程相关研究。E-mail：yangsh2006@lzu．cn
通讯作者：张虎元，男，1963年生，博士，教授，主要从事环境岩土工程研究。E-mail：zhanghuyuan@lzu．edu．cn
