塑料排水板处理软基侧向变形规律及预测模型

摘要

探讨西南地区软土路基经塑料排水板方式处理后，路基侧向变形的规律。基于四川省遂-资高速公路软土路基沉降变形监测的数据，对土体侧向变形随深度、侧向变形随时间的变化规律进行统计分析，并根据其变化特征，分别提出相应的预测模型。研究表明：（1）在路堤填筑过程中侧向水平位移近地表处（0.15～0.3倍软基厚度）侧向位移变化剧烈；（2）侧向水平位移随时间存在3种变化关系：填筑前期为Δym＝ΔSD，路堤填筑从临界填筑高度到设计填筑高度的过程为Δym＝0.15ΔSD，填筑完成后为Δym＝0.3ΔSD。最大侧向水平位移随时间大致呈“S”形曲线分布；（3）根据侧向水平位移随深度变化特点、侧向水平位移随时间变化特点，分别提出y（z）＝ae-λz（bsinλz＋ccosλz）、y（t）＝a/（1＋e（b-c·t·r））模型进行预测，预测结果与实测数据较为吻合。%This paper decides the discipline of soft soil subgrade lateral deformation after the approach of plastic drainage plate in the southwest area.Based on the project of expressway from Suining to Ziyang in Sichuan Province,we sort out the typical observation data of monitoring sections deformation.We analyze the variation law of lateral deformation from the angle of time and depth.Meanwhile we propose the forecasting model according to the characteristic of deformation.The results indicate that the following.(1 )During the process of filling,the lateral deformation near the ground surface alters violently.(2)The lateral deformation distributes three variation laws:during the filling stage,the relationship between the lateral deformation and time isΔym=ΔSD.The height from the critical filling to the design process,the relationship is Δym=0.15ΔSD.In the consolidation stage,it is Δym=0.3ΔSD.The maximum lateral deformation is distributed as S-shape with time.The maximum deformation position does not change.(3)We propose and predicte the y(z)=ae-λz(bsinλz+ccosλz)、y(t)=a/(1 +e(b-c·t·r))curve according to the variation law of lateral horizontal deformation from the angle of depth and time.The result indicates that the predicted life matches the real data.