岩溶路基注浆质量综合物探检测方法与评价研究

为研究岩溶路基注浆质量综合物探检测方法及相关检测评价标准,在南广铁路全线的岩溶路基中选取具有代表性的试验区段,对电阻率法、瞬态面波法和电磁波CT法等物探检测方法的特性和检测评判标准展开了现场试验研究。根据上述物探检测方法的适用性和经济性,提出了一种在不同工程条件下多种物探检测方法优化组合的综合物探检测方法。并通过统计分析注浆合格的岩溶路基注浆前后电阻率、面波波速及电磁波吸收系数变化规律,初步得出了上述3种检测方法的注浆质量检测评价标准:电阻率法检测合格标准为溶洞注浆前后电阻率变化率大于20%,卵石土层电阻率变化率大于10%; 瞬态面波法检测合格标准为注浆后土体波速大于20.6h+130.3,溶洞波速大于17.1h+236.9; 电磁波CT法检测合格标准为溶洞注浆前后电磁波吸收系数差值大于0.4dB m-1,卵石土层电磁波吸收系数差值大于0.1dB m-1。

COMPREHENSIVE GEOPHYSICAL DETECTION METHOD AND EVALUA-TION OF KARST ROADBED GROUTING

This paper studies the comprehensive geophysical detection method and evaluation standard of karst roadbed grouting effect. The typical test areas of Nanning-Guangzhou railway karst roadbed are selected. The field test research of detection standard and characteristics are studied using resistivity method, transient surface wave method and electromagnetic wave CT method. The applicability and economy of the above geophysical detection methods are evaluated. The comprehensive geophysical detection method of variety methods combination in different engineering conditions is proposed. The differential values of resistivity, surface wave velocity and electromagnetic wave absorption coefficient are statistically analyzed using the test data of grouting. The grouting is qualified, and preliminarily obtained in the karst roadbed. The grouting effect detection standards are proposed for the above three geophysical methods. The resistivity method detection standard is that the resistivity differential values of karst cave is more than 20%, and the pebble soil is more than 10%.The transient surface wave method detection standard is that the wave velocity of clay is more than 20.6h+130.3, and the karst cave is more than 17.1h+236.9. The electromagnetic wave CT method detection standard is that the electromagnetic wave absorption coefficient differential values of karst cave is more than 0.4dB m-1, and the pebble soil is more than 0.1dB m-1.