Development and application of a new embedded settlement gauge based on dual-pressure sensors

Since the traditional settlement plates have adverse effects on the construction with tedious operations, a new embedded settlement gauge based on the dual-pressure sensors is proposed. Based on the principles of transforming the measurement of ground settlement to that of variations on hydraulic pressure in a full-sealed system, the new embedded settlement gauge comprises a vertical sealed pipe, a standard pressure sensor and a core pressure sensor. Both laboratory and field tests are conducted to describe the detailed operation instructions, including calibration, installation and data collection. It is found that the new gauge is applicable with a precision of 2 mm and repetition error of 2 mm. Compared with the traditional settlement plate, it has several significant advantages: (1) It is embedded underground, thus there are no effects on construction; (2) The settlement can be measured only by reading the sensors, resulting in a high efficiency; (3) It can be employed to measure the post-construction settlement, leading to a low cost.