某河道治理工程中岸坡土体渗透特性分析研究

Analysis and Research on Permeability Characteristics of Bank Slope Soil in a River Regulation Project

针对某河道工程岸坡土体持水特性开展试验研究,研究了土样在脱湿过程排水量与时间为正相关,呈“先增后平稳”变化,吸力与排水量为负相关,干湿循环2次、第50 h时吸力450 kPa所排出水量相比40 kPa、150 kPa分别降低了51.7%、49.1%;吸湿过程排水量随时间呈“先减后平稳”变化,吸力与吸水量呈负相关。研究得到脱湿工况含水量高于吸湿工况,循环次数愈多,则含水量愈低,含水量与基质吸力均为负相关变化;重塑土受吸力影响更为敏感,其含水量低于原状土。获得了渗透系数与基质吸力呈负相关,受吸湿与脱湿环境影响较小;密度与渗透系数特征呈负相关,在基质吸力150 kPa时密度1.4 g/cm3的土样渗透系数相比密度1.7 g/cm3增大了1个多量级;干湿循环次数增多,渗透系数较高。

An experimental study was carried out on the water-holding characteristics of the soil on the bank slope of a river engineering.It was studied that the displacement of the soil sample during the dehumidification process is positively correlated with time,showing a"first increase and then stable"change,and suction and displacement are negatively correlated,dry and wet At the second cycle and the 50th hour,the water discharged by the suction force of 450kPa decreased by 51.7%and 49.1%respectively compared with 40kPa and 150kPa;the water discharge during the moisture absorption process showed a"first decrease and then steady"change over time,and the suction power was negatively correlated with the water absorption.The research shows that the moisture content of the dehumidification condition is higher than that of the moisture absorption condition.The more the number of cycles,the lower the water content,and the water content and the matrix suction are negatively correlated changes;the remolded soil is more sensitive to the influence of suction,and its water content is low In the undisturbed soil.It is obtained that the permeability coefficient is negatively correlated with the matrix suction,and is less affected by the moisture absorption and dehumidification environment;the density is negatively related to the characteristics of the permeability coefficient,and the permeability coefficient of the soil sample with a density of 1.4g/cm3 when the matrix suction is 150kPa is compared with the density of 1.7g/cm3 increased by one more magnitude;the number of dry and wet cycles increased,and the permeability coefficient was higher.The thesis provides a reference for studying the water retention characteristics of soil materials in water conservancy projects.