Refraction Method Applied Research In The Exploration Of Dam Disease

In the last few years, the water conservancy capital construction is already put in the more and more important position in our country economic developments. There are near 26 ten thousand kilometers embankment and 8 ten thousand reservoirs in our country, the proportion of the disease in the dike is high. Applying the method and technique of geophysics (have no damage ) have a important meaning for discovering the diseases. The main disease of the dike include: Seepage, crack, slip, cave, weak layer, collapse, pipe breach. The thesis used a lot of space describe the basic principle of shallow seismic in the refraction method, it point out that the refraction have five important characteristics: have blind area; the super-speed layer have the shield function, but the shield function is opposite; the thin layer have the choose function; the earth have the filter function. The influence factor to the refract rate have the degree of the crack, filling and geologic strata depth. Aim at the dike diseases, the thesis have a careful elucidation to the information collected of the refraction in the open country. Point out to attach importance to the investigation of interference wave,the condition of stir and receive,inspect system,the space of the detector,the length of the line,instrument factor in the process of refraction exploring. In the chapter of data explaining, it introduced eight kinds of refract methods at present: ex- wave method, add and subtract method, Hales method, delay-time method, T₀ method, exchange method, extend exchange method, the number method. Point out the most common use is T₀ method, and recommend to adopt extend exchange method to interpretate the seismic refraction. The thesis takes the example of the red mud reservoir to explain how to solve the problem of applying theory knowledge guiding to the fulfillment. The thesis refers three points of thinks and two point of fault in the use of method.The thesis concludes a set of seismic refraction methods to detect the disease of dike, provide a technique way for reference and appliance, especially recommending a more reasonable method of the seismic refraction interpretation.