Experimental Study on the Deformation Characteristics of Fine-Sandstone Under the Loading and Unloading Conditions

The deformation characteristics of the fine-sandstone is studied under the loading and unloading conditions at the three different deformation-rates and the two different stress-levels. The experimental results show that there is really the plastic-loop in the deformation curve for the loading deformation curve is different from the unloading deformation curve. But the plastic-loop is nearly unchangeable since the second circulate loading. The residual-deformation is be almost zero since the second circulate loading, and that the slope of the deformation curve increases as the deformation-rate increases, and that the residual-deformation increases as the stress-levels increases.     

THE SIZE EFFECT OF THE FRACTURE ENERGY OF CONCRETE TESTED BY THREE POINT BENDING

This paper ainalyses the size effect of the fracture energy of concrete tested bythree point bending. It is shown that positive errors of test results of fracture energy increase,ornegative errors decrease with increasing of the specimen ize. The phenomenon is one of main causesresulting in the size effect of fracture energy.     

Deformation of deep foundation pits due to excavation and dewatering considering the change of void ratio and permeability coefficient with current stress of soil

基于修正剑桥模型理论,推导了孔隙比e随土体当前应力变化的方程,同时比选了4组经典的描述渗透系数k随孔隙比变化的方程,选择了其中一组最佳的估算公式,编写ABAQUS用户子程序VOIDRI和USDFLD,以实现孔隙比和渗透系数随土体当前应力的变化。在此基础上,研究深基坑降水开挖所致的坑内外土体的变形、围护结构的变形及弯矩,得到以下结论：当考虑孔隙比随土体当前应力变化时,坑外地表沉降量、墙体的水平位移、地下连续墙的弯矩、坑底隆起量均大于孔隙比为定值时的情况;当考虑渗透系数随土体当前应力变化时,坑外地表沉降量、墙体的水平位移、地下连续墙的弯矩均小于渗透系数为定值时的情况,但同时考虑渗透系数和孔隙比变化情况时,其对坑底的隆起量的影响可以忽略不计。     

Inspiration to Reuse of Old Industry Building with SOHO

This paper analyzes the SOHO and the reuse of old industry building, and deeply explores the creation and application of SOHO mode in the reuse of old industry building, furthermore, it points out the four inspirations to the reuse of old industry building, at the end, a general judgment of the development logic of SOHO is given.     

Evolvement of Plastic-loop of Fine-sandstone Under the Loading and Unloading Conditions

The deformation characteristics and the plastic-loop of the fine-sandstone is studied under the loading and(unloading) condition at the three different deformation-rates and the two different stress-levels,the results show: 1) There is really the plastic-loop in the deformation curve for the loading deformation curve is different form the unloading deformation curve.But the plastic-loop is nearly unchangeable since the second circulate loading.2) There is different for every imitational parameter between the first deformation curve and the second deformation curve at the different stress-levels and the different deformation-rates,but every imitational parameters become more and more invariable gradually since the second circulate curve.3) With the change of the deformation-rates and stress-levels,the imitational(parameters) will change with it.4) The imitational parameters are different for loading section and unloading section of the fine-sandstone deformation curve at the same circulate curve under the same deformation-rate and stress-level.