Theory Study And Engineering Application Of Intergrated Tracer Methods For Leakage From Embankment

Detection of the leakage from embankment is a complex and important study problem. There are condition, limitation and multi-results with the traditional detection methods, which are based on geophysical exploration. Especially the traditional detection methods are helpless when dealing with the leakage passage, whose depth of burial is great while spatial sizes are small. The tracer method, which is based on flow, temperature, and chemistry fields, can make up the shortage of geophysical exploration. The paper analyses and summarizes the tracer method, which was formed by predecessors to detect the leakage from embankment. Then the tracer method is further discussed on some theories and engineering application. The content and result of study are as follows.1. The paper discusses the species and accuracy of the instruments for measuring temperature, influential factors of temperature in the borehole, and the elimination and adjustment methods of the influential factors except the groundwater motion. The heat source functions of formation temperature, which is affected by line heat source, are expounded. Leakage water, which is in the leakage passage, was taken as continuous line heat source. Based on heat source method of heat conduction, the continuous line heat source model of embankment's leakage was made, combing definite boundary conditions, and a formula for calculating seepage velocity was derived. In the engineering case, based on the temperature measured in the borehole, the value calculated of seepage velocity by the formula is very near to the one measured directly with the method of radioisotopic tracing.2. Because there are some questions about the traditional point dilution formula and the generalized dilution formula deduced by predecessors, a new dilution formula was derived to calculate seepage velocity with tracer method, based on the condition that there existed vertical flow in the borehole and a reasonable physical model was adopted, considering the seepage velocity as a function of tracer dilution time. When there was vertical flow in borehole, by the comparison between results of three formulas and the error analysis, it was shown that the...