摘要
为探究不同风化程度花岗岩土层的力学特性,通过原位与室内直剪试验对云南景洪市花岗岩残积土层和全风化花岗岩土层的抗剪强度进行了对比分析。原位试验结果表明,花岗岩残积土层的抗剪强度低于全风化花岗岩土层,但随着竖向应力增加,花岗岩残积土层的抗剪强度增量更大。在浸水条件下,2种土层的抗剪强度均有所降低,随着竖向应力的增加,浸水条件对花岗岩残积土层的影响减弱,对全风化花岗岩土层的影响加强。通过原位与室内试验结果比较发现,花岗岩残积土层的原位抗剪强度低于室内试验,而全风化花岗岩土层的原位抗剪强度高于室内试验。分析表明:花岗岩残积土层中天然裂隙和不连续面的存在,是导致其在原位条件下抗剪强度较低的主要原因,在工程设计中应慎重使用室内试验结果评估花岗岩残积土层的抗剪强度,确保设计的安全性和可靠性。而全风化花岗岩土层则由于本身较为均匀的结构特性和原位试样尺度效应的影响表现出较高的抗剪强度。
To investigate the mechanical properties of granite soil layers with varying degrees of weathering,a comparative study of shear strength was conducted between granite residual soil layers and completely weathered granite soil layers in Jinghong City,Yunnan Province,using in-situ and laboratory direct shear tests.The in-situ test results indicated that the shear strength of granite residual soil layers was lower than that of completely weathered granite soil layers.However,as the vertical stress increased,the incremental gain in shear strength was greater for granite residual soil layers.Under water immersion conditions,the shear strength of both soil layers decreased.With increasing vertical stress,the effect of immersion on granite residual soil layers weakened,while the effect on completely weathered granite soil layers intensified.A comparison between in-situ and laboratory test results revealed that the in-situ shear strength of granite residual soil layers was lower than that obtained in laboratory test,whereas the in-situ shear strength of completely weathered granite soil layers was higher than that observed in the laboratory.The primary reason for the lower in-situ shear strength of granite residual soil layers was attributed to the presence of natural fractures and discontinuities within the soil,suggesting that laboratory test results should be used cautiously to assess the shear strength of granite residual soil layers in engineering design to ensure safety and reliability.In contrast,completely weathered granite soil layers exhibited higher shear strength in-situ due to their relatively uniform structural characteristics and the influence of scale effects on in-situ samples.
作者
瞿嘉安
王志良
蒋玉
左琳
QU Jiaan;WANG Zhiliang;JIANG Yu;ZUO lin(Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming 650600,China;School of Engineering and Technology,Baoshan University,Baoshan 678000,China)
出处
《自然灾害学报》
北大核心
2025年第5期172-180,共9页
Journal of Natural Disasters
基金
云南省科技厅青年科学研究项目(202401BA070001-047)
云南省教育厅科学研究基金项目(2023J1131)
国家自然科学基金项目(42067043)
云南省闻邦椿院士工作站项目(202205AF150032)。
关键词
花岗岩残积土
全风化花岗岩
原位直剪试验
抗剪强度
工程设计
granite residual soil
fully weathered granite
in-situ direct shear test
shear strength
engineering design
作者简介
瞿嘉安(1993-),男,讲师,博士,主要从事岩土工程方面的研究。E-mail:936868365@qq.com;通信作者:王志良(1982-),男,教授,博士,主要从事岩土工程方面的研究。E-mail:wangzhiliangtj@126.com。
