Abstract: Aiming at the existing problems of vacuum pressure measurement method in drainage plates, the definition of vacuum pressure in drainage plate was expounded, and the measured results of the piezometers and vacuum gauges were analyzed through theoretical analysis and field tests. The test results show that the measured results of the piezometers and vacuum gauges cant be used as vacuum pressure directly, and the water level and settlement in drainage plate should be corrected. The revised formulas for calculating the vacuum pressure in drainage plate were derived from the measured results of the piezometers and vacuum gauges. According to the measured results of the field test, the measured results of the piezometers can be used to calculate the vacuum pressure in drainage plate. The parameters are easy to obtain, the calculation is simple, and the calculated values are in line with the reality and the stability is good. However, the method of using the measured results of vacuum gauges to calculate the vacuum pressure in drainage plate has many parameters. It is difficult to accurately measure and is complicated to calculate; meanwhile, it has many assumptions of formulas, large deviation of results and poor test stability. It is recommended that piezometers should be used to monitor the vacuum pressure in drainage plate in practical engineering.

Key words: vacuum preloading, piezometer, vacuum gauge, vacuum pressure in drainage plate, modification equation

摘要： 针对目前排水板内真空压力具体测量方法存在的问题，阐述了排水板内真空压力的定义，并通过理论分析及现场试验对孔隙水压力计 及真空表实测结果进行分析。试验结果表明：孔隙水压力计及真空表实测结果不能直接作为真空压力使用，应对排水板内水位及沉降进行修 正。推导了孔压计及真空表实测结果计算排水板内真空压力的修正公式。根据现场实测结果，孔压计实测结果计算排水板内真空压力，参数 简单易得、计算简便、计算值较为符合实际且稳定性较好。而真空表实测结果计算排水板内真空压力，参数较多且难以准确测定、计算复杂 、公式假定较多、结果偏差较大且测试稳定性较差。在现场实际工程中，建议采用孔压计监测排水板内真空压力。

关键词: 真空预压, 孔隙水压力计, 真空表, 排水板内真空压力, 修正公式