不同胶结剂人工结构性黄土的力学特性差异研究  

Study on the difference of mechanical properties of artificial structured loess with different binders

作　　者：李宏儒[1,2] 梁恒楠 LI Hong-ru;LIANG Heng-nan(School of Civil and Architectural Engineering,Xi’an University of Technology,Xi’an,Shaanxi 710048,China;Shaanxi Provincial Key Laboratory of Loess Mechanics and Engineering,Xi’an University of Technology,Xi’an,Shaanxi 710048,China;Nanyang Normal University,Nanyang,Henan 473061,China)

机构地区：[1]西安理工大学土木建筑工程学院,陕西西安710048 [2]西安理工大学陕西省黄土力学与工程重点试验室,陕西西安710048 [3]南阳师范学院,河南南阳473061

出　　处：《岩土力学》2023年第5期1416-1424,共9页Rock and Soil Mechanics

基　　金：陕西省黄土力学与工程重点试验室项目(No.13JS073);陕西省自然科学基础项目(No.2017JM5059)。

摘　　要：黄土是一种具有显著结构性的土,由于原状黄土存在非均匀性、各向异性、原位取样扰动性以及试验重复变异性等因素,如何人工制备一种结构性黄土,能真实地反映原状黄土的力学特性,值得研究。针对已有向重塑黄土中添加水泥、石灰和新型岩土添加材料路液来制备结构性土的这些方法,研究了不同添加剂对人工结构性黄土的力学特性影响的差异性。研究结果表明:路液作为添加剂制备的结构性土随路液含量的增大,结构强度先增大后减小,不同于水泥和石灰随添加量增大、抗剪强度持续增大这一特点;在不同围压下,添加路液制备的结构性土,其应力-应变曲线演化规律较符合原状黄土的力学特性;3种添加剂制备的结构性土抗剪强度随含水率变化具有陡降区和平缓区的差别,在含水率小于塑限的陡降区,抗剪强度急剧降低,而在平缓区变化缓慢,趋向于重塑土;不同添加剂对人工结构性黄土摩擦角φ的影响较小,但对黏聚力c影响显著。研究成果有助于认识常用胶结剂对土力学性质改变的特性,也可为制备设定力学参数的人工结构性黄土的技术提供理论与技术指导。Loess is a type of soil with metastable structure.Due to the inhomogeneity,anisotropy,disturbance of in situ sampling and repeated variability of tests of undisturbed loess,how to manually prepare a structured loess that can more accurately reflect the mechanical properties of undisturbed loess is worth studying.Based on the existing methods of preparing structured soil by adding cement,lime and new rock and soil materials Roadyes to remolded loess,this study investigates the influence of different binders on the mechanical properties of artificial structured loess.The research results show that the structural strength of the structured soil prepared with Roadyes as the binders increases first and then decreases with the increase in Roadyes content,which is different from the characteristics that the shear strength of cement and lime increases continuously with the increase in the addition amount.Under different confining pressures,the evolution of the stress–strain curve of the structured soil prepared with Roadyes is more consistent with the mechanical properties of the undisturbed loess.The variation of shear strength of structured soil prepared with three binders can be divided into steep drop stage and stable stage with the change of water content.At the steep drop stage where the water content is less than the plastic limit,the shear strength decreases sharply,but changes slowly at the stable stage,which resembles the remolded soil.Different binders have little influence on the friction angle φ of artificial structured loess,but have significant influence on the cohesion c.The research results are helpful to understand the soil mechanical properties changed by common binders,and also provide theoretical and technical guidance for the preparation of artificial structured loess with preset mechanical parameters.

关 键 词：人造结构性土 胶结剂 结构强度 应力-应变曲线 抗剪强度 

分 类 号：TU411[建筑科学—岩土工程]