工程粘性土体的特殊性质

工程粘性土体所具有的许多难以用常规连续介质力学方法描述的特殊性质，造成了定量评价其工程性质的困难。这就使得我们必须考虑从土的自身结构特征出发来重新认识土体以寻找新的解决途径。作者的论文首先评介了粘性土微结构的研究史和发展现状及趋势，结合我国的情况，指出了当前存在的问题和急待解决的问题；接着介绍了作者研制的用于原状速冻样品干燥的温差真空升华装置。它在制样速度上超过了国内和苏联报道的同类产品。为后继工作提供了可靠的前题；作者同合肥工业大学计算机与信息系共同研制的粘土微观结构图象计算机分析系统是我国首次利用计算机作粘土结构的定量研究。它的研制成功，使粘土结构的定量化工作达到了一个新的领域；文中还利用了系统科学的方法，对工程粘性土进行了系统分析，从系统观的角度提出了粘土结构、结构层次、结构状态的概念，并划分了粘土的结构层次，指出了主要结构层次，从而澄清了模糊不清的土结构概念问题。由此，作者从工程粘性土的特征出发，引入了结构熵的概念认为熵可以用来作为评价粘性土系统结构状态的一个定量参数，并阐述了它的性质，从而使结构研究的定量化有了一个新的途径；作者以宁波粘土为例，用力学试验和结构定量分析的数据论述了压应力作用下的粘土熵减规律及微结构要素的变化规律，指出在大于一定压应力时粘土要素要出观彼此聚合和形状向扁平发展的现象。并给出了宁波粘土这些结构变化的经验公式。随后，作者分析了结构变化的机制即进化机制。探讨了粘土非线性应力应变、各相异性、非常规硬化的形成原因；最后，作者指出了这些微结构参数与粘土力学性质的关系，并认为应用微结构参数参与粘性土性质的评价、分类、岩石风化研究、湿陷性黄土研究以及建立真正的土的本构关系将有可观的前景。
工业羊毛毡
Many special behaviours owned by engineering clay can not bedescribed with the methods of conveniently continuous mediummechanics,which makes it difficult to appraise the engineeringcharacters of clay quantitatively.So, it is imperative tore-observe the clay from the structureal features of theclay itself to look for a new way for estimate it.At first of this present paper, the author points out theproblems existing nowadays and the problems to be solvedurgently combining the case in China based on analysis ofhistorical and present situation as well as the tendency of claymicrostructure researches.Then, it introduces a Tempreture Graded Vaccum SublimationInstrument designed by the author to dry the undisturbed freezesamples, which has supassed that reported in Chinaand that in U.S.S.R in the speed of sample preparation and whichprovides a reliable premise for later work.Cooperated with the Computer and Information Department inHEFEI Polytechnic Univesity, the author make researches on thecomputer system for analysing the image of the microstructure ofclay,which is the first time to make quantitative study onclay structure with computer in China.Its success has brought thequantification work of clay structure to a new field.The systematic scientific method is used in the essay to makesystematic analysis on engineering clay.The concepts are putforward about engineering clay structure, the level of structureand structure state from the viewpoint of system.The levels ofclay structure is classfied and the main structure level ispointed out,which make clear the vague concept of claystructure.The author then introduces the concept of structureentropy from the features of engineering clay,considering thatthe entropy can be used as a quantitative parameter to appraisethe structure state of clay system,and its characters are set forth.This opens a new way for quantitative study of soilstructure.Taking NINGBO clay as an example, the author expounds thereducing laws of clay entropy and the changing laws of theelements of microstructure with the data of mechanicalexperiments and the quantitative analysis of clay’s structurethat when the pressure stress get to a certain value the clayparticles will have the phenomenen of mutual polymerization andthe phenomenon that the pattern of particle Io be flat,and theexperienced formulas of the structure change of NINGBO clayare given.Then the author analyse the mechanism of structurechange e.g evoluting mechanism,discuss the resources ofthe non-linear stress and strainrelationship,unisotropy,and unconvenient strain handening ofclay.At last,the author point out the relationship between theparameters of microstructure and the mechanical properties ofclay. It is thought that will be a bright future by using theparameters of microstructure to help appraising the claybehaviors,clay classification, rock weathering study,collapsibleloess research and to help establishing the real constitutiverelation of soil.