一种借助振动台测定土体剪切波速的新装置及试验验证

A New Device to Measure the Shear Wave Velocity of Soil Samples with Vibration Table and Its Experimental Verification

为了研究桩基加固前后地基土剪切波速的变化及大小,借助于振动台、压力传感器、动态采集系统等设备发明了一套在室内测定土体剪切波速的新装置。该装置只有振动方向的剪切波,不存在其他形式波的干扰,具有操作方便、简捷,计算直接、简单的优点,可以有效地减小试验所带来的误差。利用该装置分别对天然地基土和9桩加固地基土的剪切波速进行了试验测试,计算结果和相关文献得到的结果相近,进一步验证了该装置测试土体剪切波速的可行性。桩基加固后地基土的剪切波速相比天然地基有所提高,土的抗液化强度增强。

In order to study the change of shear wave velocities of the foundation before and after pile strengthening, a new device was developed to measure shear wave velocity of soil in laboratory with the help of vibration table, pressure sensor and dynamic collect system. The device generates only shear wave coming from the vibration direction and avoids interruptions by other waves. It has a lot of advantages such as easy operation and simple calculation, etc. which can effectively reduce the experiment error. The shear wave velocities of a natural foundation and a foundation with 9 pile reinforcement were tested using the device, and the calculation results were compared with relevant literature. The calculation results are close to the results obtained in this experiment, which proves the feasibility of using this device to determine shear wave velocity of soil. The test result also shows that the shear wave velocity of pile reinforcement foundation is higher than natural soil, which means the liquefaction resistance of the soil has been improved.