【作者】 冀国栋；

【导师】 杨春和；

【作者基本信息】 重庆大学 ， 矿业工程， 2014， 博士

【摘要】 在我国，大约90%以上的盐岩资源采用钻井水溶采矿方法进行开采，目前已经形成了大量废弃的地下盐腔，这些废弃盐腔如果不进行妥善处置，容易诱发多种地质灾害，主要表现为形成大面积地表沉陷和卤水出冒污染地下水。同时，我国制碱工业产生的碱渣，长期以来采取地面堆放的处理方式，占用土地资源，破坏周围的生态环境。将碱渣回填到地下盐腔，把盐腔内的卤水置换出来，既能有效规避废弃盐腔造成的地质隐患，又能减小碱渣地面堆放对环境的污染破坏。本文以江苏矿区碱渣回填地下盐腔工程为依托，针对碱渣-卤水混合浆体的特性，系统展开了沉降和力学试验研究，根据碱渣-卤水混合浆体沉降后形成沉积层的变形规律，建立了考虑地下盐腔内碱渣沉积层强度变化的数值模型，结合数值模拟的手段对碱渣回填提高地下盐腔的稳定性进行了研究，主要研究内容及结论如下：1.模拟地下盐腔的温度条件和卤水环境，进行了不同初始浓度的碱渣-卤水混合浆体沉降试验，研究了碱渣浆体的沉降以及扩散特性。对比了不同初始浓度下的碱渣浆体沉降过程和沉降类型的区别，研究了初始浓度对碱渣浆体沉降以及扩散特性的影响。2.分析了碱渣-卤水混合浆体沉降后形成沉积层的结构特征。对碱渣沉积层进行了低压和高压固结试验，研究了碱渣沉积层的变形规律，得到了松散淤泥质碱渣沉积层在0.1kPa-3.2MPa压力范围内的固结曲线，对地下盐腔内回填碱渣的物理参数进行了初步预测。3.利用粉煤灰对碱渣沉积层的强度特性进行了改良。对掺入粉煤灰的复合碱渣沉积层进行了组成、力学和细观试验，研究了复合碱渣沉积层的力学强度特性，分析了粉煤灰提高碱渣沉积层强度特性的机理。4.分析了地下盐腔体积收缩变形的规律，研究了碱渣回填提高地下盐腔短期稳定性和长期稳定性的机理，揭示了碱渣回填抑制地下盐腔体积收缩的主要影响因素。5.考虑地下盐腔的体积收缩，基于固结试验的结果，建立了表征地下盐腔内回填碱渣强度特征的数值模型。对比分析了地下卤水溶腔和碱渣回填腔的长期蠕变结果，研究了碱渣回填对地下盐腔稳定性的影响。6.以江苏矿区碱渣回填地下盐腔为工程背景，进行了地下连通腔群稳定性的数值模拟分析，预测了不同参数的碱渣回填后地下盐腔长期稳定性和地面沉降的情况。更多还原

【Abstract】 In China, more than90%of salt resources are explored with the method of solutionmining, leaving a large number of underground salt caverns. If these salt caverns are notabandoned appropriately, they will induce various geological hazards, mainly large-areasubsidence and pollution of underground water because of brine ooze out. At the sametime, alkali wastes generated from soda ash production are mostly accumulated aboveground, which not only occupy the land, but also deteriorate the surroundingenvironment. However, the project that alkali wastes are backfilled to undergroundcaverns and replace brine, is able to avoid the geological hazards which may be inducedby abandoned salt caverns, and eliminate the pollution by ground accumulation of alkaliwastes. According to the properties of the alkali wastes-brine mixed slurry, systematicsettling and mechanical tests have been conducted for backfilling alkali wastes intounderground salt caverns in Jiangsu. Considering the strength change of alkaliwastes sediments in underground salt caverns, a numerical model has been built basedon the deformation behavior of sediments. The stability of underground salt caverns hasbeen researched by numerical simulation method. The main contents and conclusionsare as follows:1. Considering the temperature and brine in underground salt caverns, settling testsof alkali wastes-brine mixed slurry with different initial concentration were carried outto study the settling and diffusion properties. The settling process and type of alkaliwastes were compared to investigate the influence of initial concentration on the settlingand diffusion properties.2. The sediments of alkali wastes-brine mixtures were investigated andlow-pressure and high-pressure consolidation tests were carried out to study thedeformation behavior of alkali wastes and the consolidation curve ranging from0.1kPato3.2MPa. The physical parameters of backfilled alkali wastes were predicted.3. Fly ash was used as adulterant to treat the alkali wastes sediments. Mineralcomponents, mechanics and microscopic tests were conducted to reveal the mechanicalproperties of compound alkali wastes sediments. The amelioration mechanism wasanalyzed.4. By analysis of the salt caverns volume shrinkage, the mechanism of enhancingthe short-term and long-term stability by alkali wastes backfilling was studied and the main influence factors were presented.5. Considering the volume shrinkage of underground salt caverns, a numericalmodel which represents strength properties of alkali wastes was built based onconsolidation tests. Based on the long-term creep of underground salt caverns, theinfluence of alkali wastes backfilling on the stability of salt caverns was studied.6. On the basis of backfilling alkali wastes into underground salt caverns in Jiangsu,the stability of underground salt cavern and the surface subsidence was predicted bynumerical simulation analysis.更多还原