基于路堤填筑试验的粗粒盐渍土路基防治对策研究

Study on Control Countermeasures of Coarse-grained Saline Soil Subgrade Based on Embankment Filling Test

内陆寒旱区含盐粗粒土广泛分布,选用适宜的路基填料和防治方案避免路基发生盐胀、溶陷、腐蚀等病害成为盐渍土地区路基修筑的难点问题。为了解决上述问题,借助工程地质勘察、室内试验、现场载荷试验及大型路基填筑试验,阐释了含盐粗粒土的路用性能,揭示了路基盐胀变形的规律与路基温度变化模式,基于此提出路基盐胀变形预测模型。面对现行行业规范对路基填料、场地适宜性评价结果与寒旱区公路工程修筑后的反馈信息存在偏差的问题,建议配合路基盐胀预测模型与路基容许变形量进行综合评价。研究指出粗粒盐渍土存在盐胀结构层,基于此提出路基结构设置盐胀抑制层的防治思想。路基填筑试验表明,采用加筋法处治粗粒盐渍土路基效果良好,可有效抑制盐胀。

Given the wide distribution of coarse-grained saline soil in the inland cold and arid areas,the selection of appropriate subgrade fillers and prevention and control plans that can avoid salt swelling,subsidence and corrosion is a challenge for the subgrade construction in saline soil areas.To solve these problems,with the help of geological survey,laboratory test,field load test and large subgrade filling test,the pavement performance of coarse-grained saline soil was explained,and the law of salt swelling and deformation of subgrade and the change mode of subgrade temperature were revealed.On this basis,a prediction model for the salt swelling deformation of the subgrade was proposed.In view of the deviation between the evaluation results of subgrade filling and site suitability and the feedback information of highway construction in cold and dry areas in the current industry regulations,it is suggested to make a comprehensive evaluation with the prediction model of subgrade salt swelling and the allowable deformation of subgrade.The study indicates that there is a salt swelling layer in the coarse-grained saline soil,based on which,the prevention and control thought of subgrade structure with salt dilatation inhibiting layer was put forward.The subgrade filling tests show that the reinforcement method is effective in treating coarse-grained saline soil subgrade and can effectively inhibit salt expansion.