Abstract:The loess has strongly nonlinear strength characteristics. It has different strength characteristics under different stress histories. The nonlinear strength and deformation characteristics are analyzed according to the test results. The strain-controlled undrained consolidation triaxial test is performed for the normally consolidated and over-consolidated loess. The stress-strain relationship, pore pressure-strain relationship and effective stress paths of loess are investigated based on the test results. By analyzing the experimental relationship curves of stress-strain, the secant modulus of loess is calculated. The results show that the secant modulus changes with strain and depends on confining pressure. On the other hand, the mobilized cohesion and mobilized internal friction angle are calculated. It is also shown that the cohesion and the internal friction angle change with strain. The mobilization degree of strength parameters of loess is obtained under various stress states. The evolution of strength is analyzed. It is expected to have a reference for the construction of actual projects.
韩波, 李杭州, 宋丽. 原状黄土非线性强度特性试验研究[J]. 岩土工程学报, 2021, 43(S1): 117-121.
HAN Bo, LI Hang-zhou, SONG Li. Experimental study on nonlinear strength characteristics of intact loess. Chinese J. Geot. Eng., 2021, 43(S1): 117-121.
[1] 李广信. 高等土力学[M] 北京:清华大学出版社,2016.(LI Guang-xin. Advanced Soil Mechanics[M] Beijing: Tsinghua University Press, 2016.(in Chinese)) [2] 张 玉,邵生俊,刘 瑾,等.平面应变加、卸荷条件下考虑初始应力的原状黄土强度与变形特性试验研究[J].土木工程学报,2019,52(5):90-100. (ZHANG Yu, SHAO Sheng-jun, et al. Experiment study on strength and deformation characteristics of intact loess considering initial stress under plane strain loading and unloading conditions[J]. China Civil Engineering Journal, 2019, 52(5): 90-100.(in Chinese)) [3] 张 玉,何 晖,赵 敏,等.平面应变条件下原状黄土侧向卸载变形与强度特性分析[J].岩土力学,2017,38(5):1233-1242. (ZHANG Yu, HE Hui, ZHAO Min, et al. Analysis of lateral unloading deformation and strength characteristics of intact loess under plain strain condition[J].Rock and Soil Mechanics, 2017, 38(5): 1233-1242.(in Chinese)) [4] 周永习,张得煊,罗春泳,等.饱和黄土静力抗剪强度试验研究[J].岩土力学,2010,33(5):1486-1490. (ZHOU Yong-xi, ZHANG De-xuan, LUO Chun-yong, et al. Experimental research on steady strength of saturated loess[J]. Rock and Soil Mechanics 2010, 33(5): 1486-1490.(in Chinese)) [5] 方祥位,陈正汉,申春妮,等.原状Q2黄土三轴剪切特性[J]. 岩土工程学报,2008, 27(2): 383-389. (FANG Xiang-wei, CHEN Zheng-han, SHEN Chun-ni, et al. Triaxial shear properties of undisturbed loess Q2[J]. Chinese Journal of Rock Mechanics and Engineering 2008, 27(2): 383-389.(in Chinese)) [6] 李宝平,王 智,张 玉.关中地区重塑黄土强度特性三轴试验研究[J]. 铁道建筑,2017,57(8):78-82. (LI Bao-ping, WANG Zhi, Zhang Yu. Triaxial test study on strength characteristics of remolded loess in Guanzhong area[J]. Railway Engineering, 2017, 57(8): 78-82.(in Chinese)) [7] 闫芙蓉,胡雪源,崔 芳. 非饱和黄土抗剪强度特性试验研究[J]. 水利与建筑工程学报,2017,15(5): 100-104. (YAN Fu-rong,HU Xue-yuan,CUI Fang. Experimental study on shear strength characteristics of unsaturated loess[J]. Journal of Water Resources and Architectural Engineering, 2017, 15(5): 100-104.(in Chinese)) [8] 潘家军,程展林,余 挺,等.不同中主应力条件下粗粒土应力变形特性试验研究[J]. 岩土工程学报, 2016,38(11): 2078-2084. (PAN Jia-jun, CHEN Zhang-lin, YU Ting, et al. Experimental study on stress-strain characteristics of coarse-grained soil under different intermediate principal stresses[J]. Chinese Journal of Geotechnical Engineering, 2016, 38(11): 2078-2084.(in Chinese)) [9] 马倩倩,刘保健,韩 珏. 原状饱和黄土的应力-应变特性及其归一化研究[J]. 工业建筑,2016, 46(2): 68-71. (MA Qian-qian, LIU Bao-jian, HAN Yu. Research on stress-strain characteristics and normalization of undisturbed saturated loess[J]. Industrial Construction, 2016, 46(2): 68-71.(in Chinese)) [10] 张文毅,党进谦,朱彭涛,等.重塑黄土强度试验研究[J]. 水电能源科学, 2011,29(5):53-55. (ZHANG Wen-yi, DANG Jin-qian, ZHU Peng-tao, et al. Strength test analysis of reconstituted loess[J]. Water Resources and Power, 2011, 29(5): 53-55.(in Chinese)) [11] 姚爱敏,王运霞.正常固结土与超固结土主要力学性质的比较[J]. 北方工业大学学报, 2007,19(1):86-89. (YAO Ai-min, WANG Yun-xia. Comparison of characteristics between normal consolidated soil and over-consolidated soil[J]. Journal of North University of Technology. 2007, 19(1): 86-89.(in Chinese))