岩基场地检层法测井孔源距选取

The selection of source-well distance in rock foundation layer-detect method logging

检层法测井在高速铁路路基评价中受到场地地质环境条件的影响,难以获得好的原始记录;测井作业方式直接影响数据采集质量,其中孔源距的选取乃获取正确记录的关键因素之一。受地质条件影响,对于存在特殊波速结构的场地,检层法测井孔源距的选取,需要综合考虑折射波干扰、浅部低速层、纵横波分离以及套管波等四个方面影响;理论分析论证了最佳孔源距选取依据,结合沪昆高速铁路客运专线检层法测井实例对其进行验证。

Being affected by geological environmental factors in the appraisal of high-speed railway subgrade construction,it is difficult to obtain good original records using layer-detect method.Well-logging method has direct influence on the quality of data collected;the source-well distance is one of the key factors in obtaining the correct records.Because of the geological conditions,at the site where there has special wave velocity structure,the selection of source-well distance in layer-detect method must take into account four factors,namely,the refracted wave interference,shallow low-velocity layer,vertical and horizontal wave separation and casing wave;to demonstrate the basis for the selection of the optimal source-well distance through theoretical analysis,and to verify in conjunction with the case of layer-detect method in Shanghai-Kunming high-speed railway transport of passenger.