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The present work deals mainly with alunite expanding cement, its technical requirementsand hydration behaviors. Portland cement is the matrix of the cement while natural alu-nite which is used in place of calcined alunite is the expanding component, and flyashor blast furnace slag is the expanding stabilizer. Expansion, strength, self-stressing,permeability and fracture characteristics of the alunite are described. According to XRD,DTA and EM results, the characteristics of this cement in hardening... The present work deals mainly with alunite expanding cement, its technical requirementsand hydration behaviors. Portland cement is the matrix of the cement while natural alu-nite which is used in place of calcined alunite is the expanding component, and flyashor blast furnace slag is the expanding stabilizer. Expansion, strength, self-stressing,permeability and fracture characteristics of the alunite are described. According to XRD,DTA and EM results, the characteristics of this cement in hardening process are discussed. 本文研究了以硅酸盐水泥为基材,用天然明矾石代替煅烧明矾石为膨胀组分,用粉煤灰(或矿渣)为膨胀稳定剂,制造明矾石膨胀水泥的工艺特点和水化特点;阐明了该水泥的膨胀、强度、自应力以及抗渗、抗裂性能,并通过物理化学测试结果,对硬化过程中的主要性能作了讨论。 This paper deals with the analysis of results of in-situ load bearing capacity test on the worksites of five hydroelectric projects. Research has shown that in-situ load bearing capacity test is an effective method for studying the deformation and fracture characteristics of soft rock. It may be a complement to the insufficiency of laboratory studies of soft rock. The pressure deformation curves of the fracture clayrock, silty mudstone may be divided into four stages: compression of fissures, linear... This paper deals with the analysis of results of in-situ load bearing capacity test on the worksites of five hydroelectric projects. Research has shown that in-situ load bearing capacity test is an effective method for studying the deformation and fracture characteristics of soft rock. It may be a complement to the insufficiency of laboratory studies of soft rock. The pressure deformation curves of the fracture clayrock, silty mudstone may be divided into four stages: compression of fissures, linear deformation, yield of rock mass and plastic flow of rock mass.The author suggests using the point of inflection of pressure-deformation curves of rock mass around the bearing plate ( corresponding to the point of raising up of the rock mass) as the criterion of yielding limit, and using the point of departure from a straight line as the criterion of proportion limit.Stratified and fracture rock ruptures along the bedding plane at first. And then the rock mass itself ruptures gradually without obvious linear deformation. Before reaching the strength limit there is a great plastic deformation which appears to be typical plastic failure. 本文分析了在五个水电工程现场进行的载荷试验成果.研究表明,现场载荷试验是研究软岩变形、破坏特性的有效方法,可以弥补试验室对软岩某些研究的不足. 破裂粘土岩、粉砂质泥岩的压力-变形曲线可分为裂隙压密、线性变形、屈服和塑性流动四个阶段.建议用承压板周围岩体的压力-变形曲线的拐弯点(即岩体上抬点)作为确定屈服极限的标准,用板外曲线偏离直线的点作为比例极限的标准. 层状破裂岩体首先沿层面破坏,然后岩体本身逐渐达到破坏.无明显的线性变形阶段,达到极限强度前有很大的塑性变形,呈典型的塑性破坏. Based on the results of experiment with fracture toughness of reasoned body by using compact tensile samples, the fracture characteristics respecting the fracture section and direction of crack extension, etc, were described in this paper. Simultaneously, the fracture toughness was analysed, and calculated by means of J-integrals adopting the theory of elastoplastic fracture. The P—⊿ curve of reasoned body was also discussed and the conclusions were obtained respectively. 本文在作者用紧凑拉伸试件对砌石体断裂韧度测试的基础上,阐述了砌石体在断裂面、裂纹扩展方向等方面所表现的断裂特性。并用弹塑性断裂理论的J积分,计算和分析了非线性时砌石体的断裂韧度。本文还就砌石体的P—⊿曲线进行了讨论,并得出相应的结论。
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