黄泛盐渍土区路基聚盐规律与处置技术研究

发布时间：2018-12-09 11:53

【摘要】：在黄泛平原区,由于地下水位高,毛细作用剧烈,盐渍化现缘十分严重。由于对黄泛区盐渍土地基上修筑粉土路基过程中及修筑完毕后粉土路基内次生盐渍化聚盐的规律以及对路基病害影响规律的尚不清楚,公路工程中对于一般的公路路基常不做特殊处理。对于高等级公路,当区域盐渍化严重时,常采用路基内全断面设置隔断层等工程技术措施预防路基的次生盐渍化病害,尽管处治效果显著,但路基全断面隔断的技术方案=程成本高、施工时间长。分析黄泛盐渍土区路基的聚盐规律,并研究相应的工程处置技术,对于黄泛盐渍土区公路建设其有重要的理论和工程意义。本文采用室内模型试验和数值分析,研究了黄泛区盐渍土盐分聚集规律、黄泛区分层压实过程中层间聚盐问题、路基部分隔断处置的可行性及合理的部分隔断处置方案。竖管试验表明,黄泛区粉土盐分形成弱盐渍土的临界聚集高度为1.35m,当路基顶部高于毛细水最大上升高度时,在路基顶部不会产生表面聚盐现象,且路基内盐分迁移聚集的过程中,路基内不会形成明显的聚盐带。室内填筑过程模拟试验表明,在路基分层压实的过程中,各层土铺筑的时间间隔较长,在毛细作用及蒸发作用的影响下盐分在层间发生轻微聚集现象,但含盐量较低,且未出现盐分结晶；在继续填筑的过程中,毛细水不断上升,造成层间聚集的部分盐分散失,且不会造成层间压实度较大损失。基于前期研究提出的路基坡脚局部隔断技术思路,通过数值分析,提出了基于不同地下水位高度、地下水矿化度以及不同路基高度的黄泛盐渍土区路基局部隔断处置方案。通过路基聚盐模型试验和试验路,验证局部隔断处置技术方案的可靠性。采用本文的提出的黄泛盐渍土区路基坡脚局部隔断技术方案,可有效防止路基次生盐渍化病害,降低盐渍土区路基处置成本,缩短施工时间,经济效益显著。
[Abstract]:In the Yellow River plain area, the salinization is very serious due to the high groundwater level and severe capillary action. It is not clear to the law of secondary salinization and accumulation of salt in the course of constructing silty soil subgrade on saline soil foundation of Yellow River flood area and its influence on subgrade disease. In highway engineering, no special treatment is often made for general highway subgrade. For high-grade highways, when regional salinization is serious, engineering and technical measures such as setting fault-isolation in the whole section of roadbed are often used to prevent secondary salinization diseases of roadbed, although the effect of treatment is remarkable. But the technical scheme of subgrade full section partition is high cost and long construction time. It is of great theoretical and engineering significance to analyze the law of the accumulation of salt in the subgrade of the Yellow Pan-saline soil region and to study the corresponding engineering disposal technology for the highway construction in the Yellow Pan-Saline soil area. In this paper, the indoor model test and numerical analysis are used to study the law of salt accumulation in saline soil in the Yellow River flood area, the problem of salt accumulation in the middle layer during stratification and compaction in the flood area of the Yellow River, the feasibility of partial partition and disposal of subgrade and the reasonable scheme of partial partition and disposal. The vertical pipe test shows that the critical accumulation height of silt salt forming weakly salinized soil is 1.35m. when the top of subgrade is higher than the maximum rising height of capillary water, there will be no surface salt accumulation at the top of subgrade. In the process of salt migration and accumulation in subgrade, there is no obvious salt belt in subgrade. The simulation test of indoor filling process shows that in the process of subgrade stratification and compaction, the time interval of each layer of soil paving is longer, and the salt concentration is slightly accumulated in the layers under the influence of capillary action and evaporation, but the salt content is relatively low. There was no salt crystallization. In the process of continuous filling, the capillary water increases continuously, which results in the loss of some salt in the interlayer accumulation, and does not result in a large loss of interlayer compaction. Based on the local partition technology of subgrade slope foot, based on the numerical analysis, this paper puts forward the local partition and disposal scheme of subgrade based on different groundwater level height, groundwater mineralization degree and different roadbed height. The reliability of the technical scheme of partial partition and disposal is verified by the model test and test road of subgrade polysalt. By adopting the local partition technique scheme of the embankment slope foot in the salinized soil area of the Yellow River, the secondary salinization disease of the roadbed can be effectively prevented, the treatment cost of the roadbed in the salinized soil area can be reduced, the construction time can be shortened, and the economic benefit is remarkable.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.166

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