单环注水试验新装置的研制与应用

Development and Application of a New Device for Single-ring Water Injection Test

针对传统单环试坑注水试验装置在注水流量观测时存在误差大、效率低等问题,研制了单环注水试验新装置。该装置主要由马氏瓶、数字差压计、注水钢环等组成,采用数字差压计对马氏瓶内外压强差进行测量,再将测得的气体压强差换算为马氏瓶内水柱高度值,从而可计算出每个观测时间段内由马氏瓶注入钢环内的水量,性能测试结果显示注水量观测相对误差小于3.8%。采用单环注水试验新装置测试兰州新区某工程建设场地填土层的渗透系数,试验结果表明:试验场地填土渗透系数为1.03×10^(-4)cm/min~2.09×10^(-4)cm/min,属中等透水地层;入渗水在竖向与水平向的影响范围差异不大,浸润范围内土体的含水率消散较快。该单环注水试验新装置能够研究原位条件下的土体渗透及水分迁移规律,结构简单、操作方便、测试精度高。

Focusing on the issues of large errors and low efficiency in observing water injection flow rate in traditional single-ring water injection test,a new device for single-ring water injection testing has been developed.The device mainly consists of a Mariotte bottle,a digital differential pressure gauge and a water injection steel ring.The pressure difference inside and outside the Mariotte bottle is measured using a digital differential pressure gauge,and the meas-ured gas pressure difference is converted into the height of the water column inside the Mariotte bottle.Therefore,the water volume injected into the steel ring by the Mariotte bottle during each observation time period can be calculated.The performance test results show that the relative error of water injection observation is less than 3.8%.The permea-bility coefficient of the fill soil layer at a construction site in Lanzhou New Area was tested using a new single-ring water injection test device.The test results showed that the permeability coefficient of the fill soil at the test site was 1.03×10^(-4)~2.09×10^(-4) cm/min,belonging to a moderately permeable layer.The influence range of infiltration water in the vertical and horizontal directions is not significantly different,and the moisture content of the soil within the infiltration range dissipates quickly.The new single ring water injection test device can study the soil permeability and water mi-gration laws under in-situ conditions,with a simple structure,easy operation,and high testing accuracy.