井筒壁后注浆质量反射波法检测技术

Detection Technology by Reflection Wave for Backwall Grouting Quality of A Vertical Shaft

为了查明厚松散层覆盖地区的立井井筒在施工及维护过程中出现的注浆及破坏问题,采用反射地震波法对其进行无损检测.利用反射地震波法进行井壁环向和纵向测线布置,通过所获得的高频反射波波速、振幅及频率等多种地震属性参数确定井壁及壁后空间的异常范围,注浆前后的测试对比可进一步获得对壁后注浆质量的评价效果.对新建井筒、维修井筒井壁的测试研究成果表明,反射共偏移法测试时观测系统参数宜选取偏移距为0.6-0.8 m,道间距0.2-0.4m,激发点移动步距为0.2 m.根据井壁表面波速、综合主频及波形特征能对井筒表面及内部结构进行定性到半定量评价.反射地震波法在井筒壁后注浆质量检测中,其干扰因素小,现场可操作性强,探测所圈定的异常范围准确.

Many abnormal problems during the construction and application of the vertical shaft can be met under the condition of the thick unconsolidated layers.For finding out this problem,the reflection wave technology is used to evaluate the quality of backwall grouting.The loop and longitudinal surveying lines along the wall of shaft are arranged by reflection wave method.According to different seismic wave attributes,such as the velocity of high frequency reflection wave,amplitude,and frequency,the abnormal range on the wall or under the wall can be forecast.The quality and effect of back wall grouting can be acquired though detection pre-and post-grouting.The researching results of the new and old shaft survey show that the offset selected should be 0.6-0.8 m,trace interval 0.2-0.4 m,and shot interval 0.2 m.According to the velocity of wall surface,integration frequency and characteristics of the seismic wave,the structure of wall surface and inside can be assessed qualitatively and semi-quantitatively.During the detection of the quality of back wall grouting,the reflection wave method has a significant effect on inspection.So it has many advantages,for example,little interference factor,easy operation,and accurate delineation of abnormal areas.