钙质土上的海洋平台桩基安装阻力研究

钙质土具有特殊的性质,在进行桩基打桩作业时,会产生较大的阻力,施工较为困难。准确评估打桩阻力,选取合适的打桩锤是顺利完成海洋平台在钙质土上桩基安装的关键。位于沙特与科威特中立海域的油田土壤以钙质土为主,采用波动方程的方法对桩基进行了可打入分析,并与现场的实测打桩记录进行对比分析,发现实际锤击数均超过非土塞工况的上限锤击数,说明计算分析过程中低估了打桩阻力。利用桩基安装动力检测技术对打桩全程进行监测的结果显示,连续打桩过程中桩身的承载力达到设计承载力要求。根据CAPWAP得到的参数进行打桩分析,计算结果与实际锤击数吻合良好,且可供类似土质打桩可行性分析借鉴。

旋挖钻机在桥梁植入桩施工中的应用

在桥梁桩体的施工过程中,钻机是一种常用的设备,但是不同种类的钻机所应用的方向不同,最终得出的效果也很难控制。因此,需要对旋挖钻机在桥梁植入桩施工中的应用进行分析研究。首先进行桩基就位及泥浆制备,并在护筒埋设处理的基础上完成植入底座关联及钢筋笼安装,最终进行清孔处理及后期维护。实例分析结果表明:经过不同预埋深度的测验,结合旋挖钻机进行桥梁桩体的植入得出的沉降值均控制在0.3m以下,表明实际应用的效果相对较好,具有较强的应用价值。

Counter-Rotating Type Tidal Stream Power Unit Mounted on a Mono-pile

The authors have invented a unique counter-rotating type tidal stream power unit, which is composed of tandem propellers and a double rotational armature type generator without a stator. The front and the rear propellers drive, as for an upstream type, the inner and the outer rotational armatures in the counter-rotating directions respectively, which keep the rotational torques counter-balanced between both propellers and armatures. This paper investigates experimentally the output and forces acting on a pile in a water channel, to get design materials of the mono-pile type tidal stream power unit. The output is maximal at the moderate rotational speed, as the same as a wind turbine. The force acting on the pile is affected by the drag, the Karman vortex and the dynamic balances of the tandem propellers, and has dominant frequencies due to not only the individual but also the interacting rotation of the front and the rear propellers.