测试海洋工程桩-土动力响应的多荷载耦合加载装置设计与实现

结合海洋工程桩基础全生命周期的受荷特点,研制出一种测试海洋工程桩基础-土动力响应的多荷载耦合循环加载装置,该装置能同时或分别施加水平循环荷载、竖向循环荷载、水平冲击荷载。本文对装置各个模块的工作原理进行了详细阐述,并推导了各模块工作时输出力的大小和规律。其中,水平循环加载模块,通过变频电动机转轴的转动带动对心曲柄滑块机构中的滑块在导轨上水平往复运动,从而实现水平循环荷载的施加。水平冲击加载模块,变频电动机的转盘带动绕线器转动,通过钢丝绳与绕线器连接的冲击加载小车沿倾角为θ的导轨向上运动至撞击杆处时,连接在冲击加载小车上的撞击脱钩器与撞击杆发生碰撞后自动脱钩,冲击加载小车进入水平导轨,撞击安装在模型桩上的加载板,实现水平冲击荷载的施加。竖向循环加载模块,利用与变频电动机相连的钢丝绳带动小车沿导轨运动,引起与加载板相连的弹簧伸长或压缩,通过与下加载板连接的卡扣实现竖向循环荷载的施加。该装置能得到多荷载耦合作用下海洋工程桩基础动力响应及桩土相互作用导致的桩周土刚度弱化规律,对海洋工程桩基础的设计和维护具有重要意义。

Development of a multi-load coupled cyclic loading device for ocean engineering to measure the dynamic response of pile-soil

A multi-load coupled cyclic loading device is developed to test the dynamic response of pile foundation-soil in ocean engineering considering the loading characteristics of pile foundation in the whole life cycle. The device can simultaneously or separately apply lateral cyclic load, vertical cyclic load and horizontal impact load. In this paper, the working principle of each module of the device is described in detail, and the output force of each module is deduced. With regard to the lateral cyclic loading module, the slider in the center crank slider mechanism moves horizontally to and fro on the guide rail by the rotation of the rotating shaft of the frequency-converting motor to apply the lateral cyclic load. For the lateral impact loading module, with the rotation of winder driven by the frequency-converting motor ,The trolley connected to the winder by the wire rope moves upward along the inclined rail to collide the impact rod and unhook from the self-release unit,enters the horizontal guide rail and dashes against the load plate mounted on the model pile to apply impact load. As for the vertical cyclic loading module, the frequency-converting motor drives the trolley along the guide rail to make the spring connected with the loading plate stretch or compress,and the vertical cyclic load is applied by the clamp connected with the lower loading plate. The device can obtain the dynamic response of pile foundation and the law of soil stiffness degradation caused by pile-soil interaction under multi-load coupling station, which is of great significance to the design and maintenance of pile foundation in ocean engineering.