基岩灌浆过程中密度检测装置弊端分析及改进研究

Disadvantage Aspects and Improvement of a Conventional Density Test Device During the Bedrock Grouting of a Dam Foundation

通过对差压式密度检测装置测量原理的研究分析,结合该装置在灌浆现场工作状况的调查研究,探究灌浆过程中差压式密度检测结果的误差来源和装置的结构缺陷。通用型差压式密度检测装置在检测过程中,一般与灌浆主管道直接连通,受到灌浆管道中灌浆压力和浆液流速波动的影响,造成较大的测量误差和水泥浆液的浪费。研究提出将密度检测装置由串联检测改为分流并联检测,即将差压式密度检测装置从灌浆主管道移出,通过分流阀引流并联于灌浆主管道,很大程度上避免灌浆主管道不稳定环境的直接影响,有效降低灌浆密度的检测误差。

Throughout the study and analysis of the measurement principle of a differential pressure density test device and combined with the investigation and study of the working condition of this device in the bedrock grouting site,the error source of the differential pressure density test results and the structural defects of the device in the grouting process were evaluated.The following conclusions are obtained:the conventional differential pressure density test device is directly connected to the main grouting pipe in the test process,which is affected by the fluctuation of the grouting pressure as well as the flow rate of the grout in the grouting pipe,resulting in a large measurement error and the waste of the cement grout.According to the above disadvantages analysis,the density test device can be improved by removal the test device from grouting pipe through the diverter valve and then parallel connecting to the main grouting pipe.By doing this can largely avoid the unstable environment induced by the main grouting pipe and effectively reduce the grouting density testing error.