膨胀黏土增长曲线的运动学分析

Kinematics analysis on growth-curve of expansive clay

通过大量室内试验,从运动学角度对4种击实膨胀黏土样的胀缩规律进行了深入研究.研究认为,膨胀曲线、收缩曲线可统称为增长曲线,其特征表现为在最初阶段增长得快,以后逐渐减慢并趋于稳定;通过对试验数据的非线性最小平方回归分析,提出了增长曲线的回归方程;通过对增长曲线速度、加速度特征进行深入研究,揭示出膨胀、收缩过程具有许多相似性,但在本质上两者不是可逆过程,其吸水膨胀速度远大于失水收缩速度.研究结果为膨胀黏土地区的工程建设提供了重要依据.

Based on lots of expansive laboratory tests, from the kinematics angle, the swelling and shrinkage rules of four kinds of expansive clayey have been studied deeply in this paper It is presented that, swelling and shrinkage curves can be called by a joint namegrowthcurve, their characteristic manifest that, in the first phase, the curves grow rapidly and become slow gradually subsequently and gain stabilization finally By the method of Nonlinear Least Square Curve Fit (NLSF), the test data have been regressed and the regressive equation of the growthcurve are brought up By study on the velocity and acceleration characteristics of growthcurve,it is discovered that, although the swelling and shrinkage processes of expansive clayey have many similar characteristics, in nature they are not an entirely reversible process, and the velocity and acceleration of expansive clayey in the swelling process when absorbing water is much rapider than that in the shrinkage process when missing water Therefore, the important basis is provided for engineering development in expansive clayey region.