镍矿渣在滨海软土地基处理中的应用研究

发布时间：2018-06-27 15:26

本文选题：镍矿渣 + 滨海软土　；参考：《中国矿业大学》2017年硕士论文

【摘要】：随着我国经济建设和钢铁工业的不断发展,镍的需求量不断增加,而冶炼金属镍所产生的镍矿渣也越来越多,由于目前镍矿渣的处理途径较少,综合利用率较低,堆放在露天渣场的镍矿渣致使大量土地资源被占用。基于上述情况,本文以真空预压法为依托,首次尝试运用镍矿渣替代粗砂作为真空预压法的排水通道,对其在软土地基中的处理效果进行研究,以期在取得良好处理效果的同时,能够有效地处理掉镍矿渣,提高镍矿渣的综合利用率。本文首先对镍矿渣的特性进行了一系列的试验研究并与粗砂进行了对比分析,结果表明:镍矿渣与粗砂的相关性质差异较小,并具有粗砂所不具备的特定优势,在排水通道材料的相关指标上满足工程技术的要求,以镍矿渣替代粗砂来进行软土地基的处理是可行的。其次,本文对真空预压法的加固机理进行了详细分析,通过收集整理连云港滨海软土地区软基处理的相关工程实例,并对各种方法进行对比,总结了真空预压法在软基处理上的优势;结合镍矿渣的特性和相关工程经验,对现场的试验施工方案和监测方案进行了设计;根据现场实测数据,对真空预压加固过程中的膜下真空度、地表沉降、孔隙水压力、分层沉降、深层水平位移的变化规律进行了深入研究;对加固前后土层的物理力学指标、原位十字板抗剪强度以及地基承载力进行对比,结果表明:运用镍矿渣处理之后,土层的强度得到了极大的提高,满足工程设计的要求,镍矿渣用于软土地基的处理效果十分理想。最后,根据实测数据,运用多种解析法对加固区的土层进行了沉降预测,通过预测结果的对比分析,提出指数曲线法为连云港滨海地区沉降预测的适宜方法;同时又借助ABAQUS有限元软件对加固区的沉降进行了模拟,结果表明:模拟值与实测值具有相同的变化趋势,精度较高,可应用于实际工程的验证与预测。
[Abstract]:With the development of economic construction and iron and steel industry in China, the demand for nickel is increasing, and the nickel slag produced by smelting nickel is more and more. Nickel slag stacked in open-air slag fields results in the occupation of a large number of land resources. Based on the above situation, this paper first tries to use nickel slag instead of coarse sand as the drainage channel of vacuum preloading method, and study its treatment effect in soft soil foundation. At the same time, the nickel slag can be treated effectively and the comprehensive utilization ratio of nickel slag can be improved. In this paper, the characteristics of nickel slag are studied and compared with coarse sand. The results show that there is little difference between nickel slag and coarse sand, and it has special advantages that coarse sand does not have. It is feasible to treat soft soil foundation with nickel slag instead of coarse sand. Secondly, this paper analyzes the reinforcement mechanism of vacuum preloading method in detail, through collecting and sorting out the relevant engineering examples of soft soil treatment in coastal soft soil area of Lianyungang, and compares various methods. The advantages of vacuum preloading method in soft foundation treatment are summarized, combined with the characteristics of nickel slag and relevant engineering experience, the site test construction scheme and monitoring scheme are designed. The changes of vacuum degree under film, surface subsidence, pore water pressure, stratified settlement and deep horizontal displacement in the process of vacuum preloading are studied, and the physical and mechanical indexes of soil layer before and after reinforcement are also studied. The shear strength and foundation bearing capacity of in-situ cross plate are compared. The results show that the strength of soil layer is greatly improved after the treatment of nickel slag, which meets the requirements of engineering design. The treatment effect of nickel slag on soft soil foundation is very ideal. Finally, according to the measured data, several analytical methods are used to forecast the settlement of the soil layer in the strengthened area. Through the comparison and analysis of the prediction results, the exponential curve method is put forward as the appropriate method for predicting the settlement in the coastal area of Lianyungang. At the same time, the settlement of the strengthened area is simulated by Abaqus finite element software. The results show that the simulated value has the same trend with the measured value, and the accuracy is high, which can be applied to the verification and prediction of practical engineering.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

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