摘要
随着西藏自治区基础设施建设的持续推进,藏东南地区的滑坡堆积体的力学特性研究已成为工程设计中的关键问题。相对密实度作为表征土体结构紧密程度的重要参数,直接影响土体的力学特性。为深入探讨相对密实度(D_(r))对该类粗粒混合土力学特性的影响,以该地区典型滑坡堆积体为研究对象,采用大型固结排水三轴剪切试验,分析四种不同D_(r)下该类粗粒混合土的力学特性。研究结果表明,当D_(r)大于0.5时,围压在100~400kPa下试样均表现出材料软化和显著的剪胀特性,破坏剪胀率均随D_(r)的增大而增大。内摩擦角随D_(r)的增大而增加,黏聚力则呈现先增大后减小的趋势。割线模量随D_(r)和围压的增加而增大,与D_(r)近似呈幂函数关系,与围压则呈线性关系。研究成果可为该类粗粒混合土的力学性能提供理论分析与预测模型,对该区域工程设计提供指导。
As the infrastructure development continues to advance in the Tibet Autonomous Region,the study on the mechanical properties of landslide deposits in Southeast Tibet has become a critical issue in engineering design.Relative density(D_r),as a key parameter reflecting the compactness of soil structures,directly influences the mechanical behavior of soils.To investigate the effects of relative density on the mechanical properties of the coarse-grained mixed soils,taking the typical landslide deposits in this region as the study example,a series of large-scale consolidated drained triaxial shear tests are conducted under four different D_(r) conditions.The study results indicate that when D_(r) exceeds 0.5,the specimens exhibit material softening and significant dilatancy under confining pressures ranging from 100kPa to 400kPa.The failure dilatancy rate increases with higher D_r.The internal friction angle shows a positive correlation with increasing D_r,while cohesion firstly increases and then decreases with D_r.The secant modulus increases with both D_(r) and confining pressure,following an approximate power-law relationship with D_(r) and a linear relationship with confining pressure.These findings provide theoretical insights and predictive models for the mechanical performance of such coarse-grained mixed soils,offering valuable guidance for regional engineering design.
作者
武海洋
吕光东
Wu Haiyang;Lyu Guangdong(Tianjin Research Institute for Water Transport Engineering,MOT,Tianjin 300456,China;Tianjin Survey and Design Institute for Water Transport Engineering Co.,Ltd.,Tianjin 300456,China;Department of Water Conservancy and Civil Engineering,Tibet Agricultural and Animal Husbandry University,Linzhi 860000,China)
出处
《工程勘察》
2025年第6期22-30,共9页
Geotechnical Investigation & Surveying
基金
西藏土木水利电力工程技术研究中心自治区工程中心二零二四年度开放课题(XZA202405CHP2008B)。
关键词
藏东南地区
粗粒混合土
相对密实度
力学特性
Southeast Tibet
coarse grained mixed soil
relative compactness
mechanical property
