论软土力学指标的室内测试方法

分析了先期固结压力对软土力学指标的试验影响及土工试验规程中加载方式存在的问题,对软土强度室内试验方法提出了修正意见。

预应力锚索锚固效果影响因素分析

通过对目前预应力锚索设计、施工情况分析 ,提出影响预应力锚索性能的影响因素 ,并提出适当的建议。

压密注浆圆孔扩张的数值分析

利用有限元软件ABAQUS对土体中的柱形孔扩张问题进行数值计算,分析地应力场、土体力学指标对圆孔扩张时压力-扩张曲线等的影响.分析结果表明,在相同地应力场条件下,小孔半径扩张大小与注浆压力成正比,与土弹性模量成反比;在相同注浆压力条件下小孔半径扩张大小与摩擦角、凝聚力均成反比.

超氯盐渍土在雅丹地貌铁路沿线固沙试验研究

以雅丹地貌新建铁路为例,研究当地超氯盐渍土在铁路沿线固沙中的应用。通过室内土工试验和微观分析结合的方法,研究超氯盐渍土的氯离子含量、含水率、液塑限、养护温度和抗压强度的关系。研究结果表明:随氯离子含量和含水率的提高,单键键能増大,单位体积键量减少,总键能减小,导致试件的抗压强度降低;抗压强度与最佳含水率之间呈抛物线关系。加温养护后,试件孔隙率增大,抗压强度降低。对于氯离子含量超过40%的盐渍土,不但要考虑毛细现象的影响,而且需采用固化剂对氯盐进行处理。研究结果对雅丹地貌新建铁路沿线的绿色固沙有所裨益。

Initial Litter Chemical Indices as Selection Criteria of Organic Nutrient Resources for Enhancement of Soil Fertility for Smallholder Farmers in Southern Ethiopia

Nutrient release from applied organic nutrient source （ONS） depends on temperature, soil moisture, soil properties, their chemical composition and microbial activity. In order to apply ONS to fulfill the nutrient requirements of plants, knowledge of quality and quantity of chemical constituents of the ONS has paramount importance. Erythrina abyssinica （EA）, Erythrina brucei （EB） and Ensete ventricosum （EV）, the first two being nitrogen-fixing indigenous multipurpose agroforestry trees in Ethiopia, were randomly collected from Southern Ethiopia. The average total nitrogen （TN） contents of EA, EB and EV were 4.05%, 3.35% and 2.56%, respectively. Similarly, the mean total soluble polyphenolics contents were 0.052%, 0.023% and 0.19%, and the mean lignin contents were 9.7%, 12.6% and 6.5%, respectively. In general, these ONS had medium to high TN content. Thus, the ONS can be selected based on their quality, quantity and ratio of their chemical constituents as alternative or supportive organic sources. A ＂decision tree＂ is best fitted for selection of these ONS.