浅层折射法在陕北侏罗纪煤田松散层调查中的应用及效果

陕北侏罗纪煤田榆神府处于鄂尔多斯地台东部，毛乌素沙漠东南缘。由于煤层埋藏浅．积沙厚，沙层含水量大，易于发生突水溃沙事故，给矿井安全生产带来较大威胁。陕西省煤田地质局物探测量队在石圪台矿井、活鸡兔矿井、大柳塔矿等矿区先后进行了以地震折射为主的勘探工作，不仅获得了各勘探区内基岩面、潜水面等松散层的地质信息，还掌握了其古河床、古冲沟的分布情况。在石圪台矿井勘探中，根据浅部1^-2煤层反射波对折射记录续至波的干涉情况，定性圈定区内1^-2的赋存范围。经钻孔验证，连续观测浅层折射法确定的潜水面深度、基岩面深度、风化层厚度等对综采有较大影响的主要界面绝对误差均小于10m，相对误差在3％左右。

Application and Effect of Shallow Seismic Refraction Method in Jurassic Coalfield Loose Beds,Northern Shaanxi

The Shenfu and Yushen mining areas of the northern Shaanxi Jurassic coalfield is situated at the eastern part of Ordos platform, southeastern margin of the Mu Us desert. Since the coal seams are shallow buried, thick and large moisture content sand covered, thus easy to happen water bursting and sand inrush accidents, threatening coalmine safety production. The Geophysical Prospecting and Surveying Team of the Shaanxi Bureau of Coal Geological Exploration has carried out prospecting works in the Shigetai, Huojitu, Daliuta coalmines and Yushen mining area earlier or later, and gave priority to seismic refraction method, not only obtained loose bed geological information of bedrock surfaces, phreatic water surfaces etc. and also administered old stream beds, old gullies distribution status. In Shigetai coalmine prospecting, according to interference from the No.1-2 coal seam reflection wave to the secondary refraction wave, circled out hosting extent of No.1-2 coal seam in the area qualitatively. After drilling validating of main surfaces may have major impact to mechanized mining, such as phreatic water surface depth, bedrock surface depth and weathering zone thickness determined by shallow refraction method, their absolute errors are all within 10 meters, relative errors about 3%.