摘要
研究目的:静力触探是一种在铁路工程广泛应用的地质原位测试方法,现行研究中,往往仅采用数理统计方法建立触探参数与土体物理力学指标之间的相关回归公式,缺乏对触探机理的深入认识和对相应回归公式的验证。为此,本文采用数值模拟方法分析静力触探机理及土体物理力学参数变化对静力触探影响规律,并对静力触探结果与土体物理力学参数之间经验公式进行验证。研究结论:静力触探探头贯入过程中,大部分径向压缩发生在1～2倍探头直径范围内,探头端部最大径向应力发生在探头锥底面部位,切向应力大部分为拉应力。在相同触探速率下,随着地基土体不同应力比M值逐渐增大,地基土体竖向应力、剪应力、超孔隙水压力及比贯入阻力均逐渐增大;随着对数体积模量λ值增大,地基土体中径向应力、竖向应力逐渐增大,剪应力、超孔隙水压力及比贯入阻力逐渐降低。此外,数值模拟所得静力触探结果与《铁路工程地质原位测试规程》中相关经验公式符合性较好。
Research purposes： As an important in - suit testing method, cone penetration test has been accepted by more and more geotechnical engineers. The existing cone penetration application methods lack of theoretical analysis and verification of the empirical formula, often only use mathematical statistical methods to establish soil physical and mechanical parameters. This paper first analyzes the mechanism of cone penetration test in soft soils and discusses the affection of different soil physical and mechanical parameters to the cone penetration test. Moreover, verifying the empirical formulas between cone penetration parameters and soil engineering properties. Research conclusions：Numerical simulation has been employed to perform cone penetration analysis for understanding of the soil behavior during cone penetration process. During static cone penetration process, most of the radial compression occurs within 1 -2 times the probe diameter range, the maximum radial stress occurs in the underside of parts of the probe cone. In the same cone penetration rate, with the increasing of stress ratio value M, the foundation soil vertical stress, shear stress, excess pore water pressure and specific penetration resistance ratio were gradually increasing ; With the increasing of logarithmic bulk modulus h, the radial stress and vertical stress of the foundation soil were gradually increasing, the shear stress, excess pore decreasing. Furthermore, the empirical formulas between water pressure and specific penetration resistance ratio were cone penetration parameters and soil engineering properties in＂Code for in - suit measurement of railway engineering geology＂ were coincident well with numerical simulation results. This paper has a useful reference to the theoretical and applied research in the field of in situ test for geotechnical.
出处
《铁道工程学报》
EI
北大核心
2012年第6期37-44,49,共9页
Journal of Railway Engineering Society
基金
铁道部科技研究开发计划(2010G001-B)
关键词
静力触探
数值仿真
机理分析
cone penetration test
numerical simulation
mechanism analysis
