Study On Borehole Seepage Investigation And Measurement-System Design

It has get a huge loses to national economy because of seepage failure. It is significant to detect the dam/dyke leakage and seepage in rock and soil, not only in theoretic but also in practical meaning, under the low-level-water condition in none flood season, for forecasting seepage deformation and seepage failure at high-water-level during flood season.Tracer method has been widely used in seepage investigation. At the first part of this thesis, the methods and technologies in this field in the world has been described and compared. Discussing advantages and disadvantages of those theories and methods, borehole test is proved that it is the only method to measure seepage flow directly in the dam/dyke seepage investigations, while no method can do better than isotope's today.Traditional dilution theory cannot measure the velocity precisely of seepage flow for the interference of vertical flow in the multi-aquifers. Aim at this condition, after studied many theories and methods in this field, an experienced formula has been drawn out to simpler the seepage calculation, and modified errors coursed by the probe and half-life of isotope tracers.After studied many detection methods, a new probe, a control system and a set of data collective-analysis-software have been developed to measure the horizontal and vertical velocity of seepage flow in the borehole. The hardware design emphasis random-weak-signal measurement in isotope tracer method, and reliability of the system has been discussed in the third part of this thesis. By the expert repository and analyzer in software, expert system can analyze seepage condition and the reason of leakage and find out the leakage place, depth, distraction area, and possible development. Then, draw conclusions of dam/dyke's ability to burden seepage deformation.At the last part of this thesis, a field test is introduced. Though tracer method, with the theory and measurement system described in this paper, to collect leakage information in field, calculate the leakage parameters, the author finds the real reason of leakage, thus validates the mentioned theory and system.