滴灌作用下膨胀土边坡表层含水量影响因素分析

Influential analysis on water content of surface soil of expansive soil slope under drip irrigation

含水量是影响膨胀土裂隙开展的关键因素,基于控制含水量(后称"控水")的思路治理膨胀土边坡的方法具有重要的工程意义。提出利用滴灌加湿作用控制膨胀土边坡裂隙的理念。运用有限元分析方法,研究滴灌作用下膨胀土表层初始含水量、滴灌量、滴灌历时以及坡度等关键敏感性因素对边坡表层含水量的影响规律。研究结果表明:膨胀土具备较强的保水性能;初始含水量低、持时短、大间距的滴灌,不利于土体水分重分布;多点源交汇滴灌下的坡度越大,滴灌浸润范围越大。因此,可通过开启较高的滴灌临界含水量、设置较大坡度以及合理的滴头水平间距来增强膨胀土边坡表层土体的加湿效果。

Soil water content is a critical factor in the development of expansive soil fissures.The control of expansive soil slope based on the idea of controlling water content is of significant importance in engineering.A concept of conserving moisture by drip irrigation to controlling fissure development in expansive soil slope is put forward.Finite element analysis is used to calculate the critical sensitivity parameters such as initial water content in surface soil,dripping volume,dripping duration and slope gradient etc.,and they can be used to investigate how these parameters impact water content in soil slopes.The results show that expansive soil has strong water retention performance;low initial water content,short dripping duration and wide interval dripping distances are adverse to water redistribution;for the multi-point source drip heads,the greater gradient of the slope is,the larger saturation area is.Therefore,better results can be achieved by increasing critical soil water content,creating greater slope gradient,and employing more appropriate horizontal distances between the drip head.