在暂不考虑其它因素引起的基质吸力组成部分，而只考虑毛细水作用对基质吸力的贡献的基础上，引进了附加内压力概念，将基质吸力分解为毛细吸力和附加内压力两部分，进一步将低含水率非饱和土中的总有效应力区分为由基质吸力引起的有效应力及由重力和其它外力产生的有效应力两部分，基此推导出基质吸力与抗剪强度之间的关系，解释了非饱和土的抗剪强度随含水率降低、基质吸力增大而增大且相互依赖关系呈非线性等重要试验现象。

从现代损伤力学观点研究了冻土蠕变同其微结构变化的关系。在蠕变实验和微结构观测研究的基础上，选择了描述冻土微结构变化的损伤内变量，建立了内变量演化方程及冻土蠕变的一般损伤理论。这一理论可同时描述蠕变过程中的“强化”现象和“弱化”现象。还对单向压缩情形进行了具体计算并与实验结果进行了比较。

依据连续介质力学的混合物理论，讨论了饱和多孔介质的波动一般方程。其中考虑了质量耦合、初始压力及其浮力效应等。对于澄清这一研究课题中的某些基本概念，以及完善其理论体系具有重要意义。

A discrete computer method, which considers the principal characteristics of the motion of discrete particles caused by the airflow over the aeolian bedforms using a set of simple rules, is suggested to simulate the initiation and evolution of wind blown sand ripples and dunes. The results indicate that, if the grain-bed impacting and surface creep are taken into account, the model is capable of reproducing sand ripples vividly, and describing the reparation of any destroy to rippled surface, a phenomenon observed in field. If the saltation driven by the main flow and the secondary flow, the surface creep due to gravity, and the slide occurring when the slope of sand surface is larger than the angle of repose are considered, the model can simulate the formation and development of sand dunes whose shape and arrangement in space are in accordance with the landscape of typical deserts. After a further investigation into the simulation process, we draw the conclusion that the aeolian bedformsis a system of self-organization and hierarchy with a fractal character.

A unified model considering the microstructure instability and a set of complete constitutive relations, which describes the volumetric collapse and shearing collapse simultaneously, is developed for collapsible loess in the framework of the catastrophe theory. The validity of the model is verified by comparing the results calculated using the model with the data of triaxial compression tests performed on Lanzhou loess. The following characteristics of collapsing deformation are explained and reproduced successfully using the model: (1) the existence of two turning points on each deformation curve, (2) the shear curves under various stress ratios intersect one another, (3) the ratio of the shear strain to the volumetric strain is a function of the stress ratio, and (4) the initial collapse condition is approximately a circle.

An evolution model considering rheologic effects is proposed to describe the progressive failure process of soil slopes. The proposed method is illustrated using previously published examples and analyses. Some of the results obtained are impossible in conventional methods of stability analyses. To obtain a visual understanding of the mechanical mechanism of progressive failure and the evolutionary process of the local failure of slopes, a numerical simulation is presented for the whole failure process. In this way, the whole evolution process is clearly shown, from slopes of local failures near the toe, through the appearance of tensional cracks at the top, to the final landslide. This understanding of the failure mechanism is very helpful for the prediction and prevention of landslides.

定义了不均匀沙不同于均匀沙的起动概念，得出不均匀沙的主要起动规律为：各粒径沙具有不同起动风速；不均匀沙中小粒径沙的起动风速大于相同粒径均匀沙的起动风速，大粒径沙的起动风速小于相同粒径均匀沙的起动风速；不均匀沙的临界流体起动风速一般会随中值粒径的增大而增大。应用对不均匀沙起动风速的研究结果，讨论了草方格动力稳定状态的形成过程，对野外发现的草方格“优化尺度”现象给出了合理说明。

The periodic wave solutions for a class of nonlinear partial differential equations, including the Davey-Stewartson equations and the generalized Zakharov equations, are obtained by using the F-expansion method, which can be regarded as an overall generalization of the Jacobi elliptic function expansion method recently proposed. In the limit cases the solitary wave solutions of the equations are also obtained.