碎石垫层已广泛应用于土木工程各个领域,但碎石垫层的强度与变形特性尚不十分清楚,需要进一步研究。通过对5种不同厚度碎石垫层在高应力下的室内模型试验和有限元分析,揭示了不同厚度碎石垫层的强度特性和变形特征。通过有限元分析与试验结果的对比分析,得出了不同厚度的碎石垫层荷载与沉降变形、竖向应力与侧向约束力都近似呈线性变化。碎石垫层的厚度对沉降大小有一定影响,在其他条件相同的情况下,碎石垫层越厚,沉降越大。在一定荷载作用下,碎石垫层在较短的时间内自身压缩变形已基本趋于稳定,而后随时间的增加,其压缩变形量很小。提出了一种测定碎石类土侧压力系数、泊松比及变形模量的试验测定方法,以期为测定其他类别土的侧压力系数、泊松比及变形模量提供参考。
Gravel cushion has been widely applied to various fields of civil engineering; but its strength and deformation characteristics is still not very clear; so it is needed to further study. Through the laboratory model test and finite element analysis of the gravel cushions with 5 different thicknesses in high stress, the strength and deformation characteristics of gravel cushions with different thicknesses are revealed. Comparing the finite element analysis and test result, the variation characteristics are obtained that the load and deformation, the vertical stress and lateral pressure of gravel cushions with different thicknesses are approximately linear. The thickness of gravel cushion has some effect on the settlement. All else being equal, the settlement increases with the thickness of gravel cushion increasing. Under certain loads, the compressive deformation of gravel cushion approximately trends to be stable within a short period of time; and then the variation of compressive deformation is less as time increases. A test determination method is proposed to measure the lateral pressure coefficient, Poisson's ratio and deformation modulus of gravel soil, so as to provide references for other soils.