Mechanical mechanism analysis of tension type anchor based on shear displacement method

Based on the fact that the shear stress along anchorage segment is neither linearly nor uniformly distributed, the load transfer mechanism of the tension type anchor was studied and the mechanical characteristic of anchorage segment was analyzed. Shear stress-strain relationship of soil surrounding anchorage body was simplified into three-folding-lines model consisting of elastic phase, elasto-plastic phase and residual phase considering its softening characteristic. Meanwhile, shear displacement method that has been extensively used in the analysis of pile foundation was introduced. Based on elasto-plastic theory, the distributions of displacement, shear stress and axial force along the anchorage segment of tension type anchor were obtained, and the formula for calculating the elastic limit load was also developed accordingly. Finally, an example was given to discuss the variation of stress and displacement in the anchorage segment with the loads exerted on the anchor, and a program was worked out to calculate the anchor maximum bearing capacity. The influence of some parameters on the anchor bearing capacity was discussed, and effective anchorage length was obtained simultaneously. The results show that the shear stress first increases and then decreases and finally trends to the residual strength with increase of distance from bottom of the anchorage body, the displacement increases all the time with the increase of distance from bottom of the anchorage body, and the increase of velocity gradually becomes greater.     

氰化渣的无害化处置试验研究

研究了采用二氧化氯氧化—硫酸亚铁配合沉淀工艺无毒化处置银矿石氰化浸出渣,考察了氧化剂种类和用量、固液质量体积比、反应时间对处置效果的影响。结果表明:对于100 g氰化浸出渣,加600 g水搅拌使形成悬浊液,调pH=10,加入8 g/L二氧化氯溶液250 mL,搅拌5 h后过滤,得到滤渣为普鲁士蓝,滤渣中铜、锌、铁质量分数分别为17.8%、20.4%和19.7%,氰未检出;滤液调pH=6,加入FeSO_4·7H_2O 2.5 g/L,曝气搅拌1 h后pH=6.5,铜、锌、铁质量浓度分别为0.5、0.5、2.8 mg/L,氰质量浓度0.4 mg/L,达到GB 8978—1996一级排放标准。     

梧桐河流域水文特性

分析了梧桐河流域自然地理概况及降水、蒸发、暴雨洪水、径流、水质等水文特性。     

边坡和基坑联合支护体系的工程应用

随着工程建设的开展,高填深挖的项目越来越多,既要考虑上部土体的边坡永久支护,又要考虑下部地下室开挖的基坑支护,于是设计计算中势必需要考虑边坡和基坑的联合支护体系。但相关规范规程尚未提供该联合支护体系的具体设计计算方法。本文结合具体工程实例,介绍了边坡和基坑联合支护体系的设计计算思路,并进行了具体设计计算,基坑开挖过程中未出现任何监测报警和现场安全事故。现工程已竣工三年多,边坡支护位移基本上处于稳定状态,可为类似工程提供思路和借鉴。