砒砂岩土壤水分入渗规律及适用模型研究

Study on Horizontal Infiltration Law and Model Test of Pisha Sandstone Soil

【目的】以内蒙古准格尔旗典型的砒砂岩土壤为研究对象,研究体积质量变化对砒砂岩土壤入渗特性的影响及适用模型。【方法】采用室内模拟土柱法,对3组砒砂岩土壤RS(紫红色)、HS(粉红色)和WS(灰白色)分别进行水平土柱积水入渗试验,研究不同体积质量(1.30、1.35、1.40、1.45、1.50 g/cm3)对水分入渗规律的影响。【结果】砒砂岩土壤垂直入渗中,入渗率、湿润锋运移速率与时间呈幂函数递减关系。体积质量的大小影响砒砂岩土壤入渗能力,体积质量越大,入渗率、累计入渗量越低,湿润锋运移越慢;Philip模型及Kostiakov模型均适用于模拟不同体积质量影响下的垂直入渗过程,其中Kostiakov模型拟合精度更高;建立能够直接反映体积质量与入渗率关系的Philip改进模型,并通过r检验法验证了改进模型具有较高模拟精度。【结论】改进的模型更适用于模拟土壤入渗特性。

【Objective】The soil developed from the typical sandstone of Zhungeer Banner in Inner Mongolia was taken as the research object,and the influence of bulk density on the horizontal infiltration characteristics of the sandstone soil was investigated.According to the color,it is divided into purple red sandstone soil(RS),red and white sandstone soil(HS)and gray white sandstone soil(WS).【Method】The horizontal bulk soil water infiltration test method is used to study the bulk density of 1.30.The effects of five gradients of 1.35,1.40,1.45,and 1.50 g/cm3 on the infiltration of water.【Result】The overall trend of infiltration rate decreases with time,and the curve generally goes through three stages:rapid decrease,slow decrease,and stable stage;cumulative infiltration increases with time and has a power-fit relationship with time;infiltration In the initial stage,the migration rate of the wet front is relatively fast,and then with time,the migration rate of the wet front gradually decreases and stabilizes after a certain period of time.The improved model more is applicable to simulate soil infiltration characteristics The bulk density has a significant effect on the infiltration capacity of the sandstone soil.Its wet front migration rate,cumulative infiltration amount,and infiltration rate all decrease as the bulk density increases.The Philip model and kostiakov model are used to fit the infiltration process.The relevant infiltration parameters were obtained,and the applicability of the two to simulate the infiltration process of sandstone soil was verified,and a model of infiltration of sandstone soil under different bulk density conditions was established.