等质量圆形基础与风电空心锥形基础承载特性

空心锥形钢筋混凝土基础是一种新型陆地风电基础形式。通过开展数值模拟,研究了在钢筋混凝土用量相等情况下,空心锥形基础与传统重力式圆形基础在水平荷载、竖向荷载及弯矩作用下的承载特性和基础周围土体变形规律,探讨了基础尺寸、比尺效应对基础承载力和土体变形的影响。研究表明:相较于圆形基础,空心锥形基础水平承载力提高幅度为202%～456%,并能有效控制基础位移;弯矩承载力大幅提升5.1～7.9倍;竖向承载力最大提高35.5%。空心锥形基础水平极限承载力随径高比(基础顶面直径与高度之比)的增大逐渐减小,竖向与弯矩极限承载力随径高比的增大而增大。随锥形基础径高比增加,在水平荷载和弯矩作用极限状态下,基础周围土体隆起量逐渐减小;竖向载作用下,土体变形范围逐渐增大。对基础极限承载力进行无量纲化处理,研究比尺效应对其影响,发现比尺效应对基础竖向承载力影响较大,对水平和弯矩承载力影响较小。

Bearing behavior of Cone-shaped hollow reinforced concrete foundation (CHRF) and the circular foundation for wind turbines under same reinforced concrete usage

The cone-shaped hollow reinforced concrete foundation (CHRF) is an innovate type of wind turbine foundation. Numerical simulations were carried out to explore the vertical, horizontal and moment bearing capacities and the soil deformation behavior of the CHRF and regular circular gravity-based foundation under the same concrete usage. The effects of the foundation sizes and the scale effect were discussed. It was found that the horizontal bearing capacity of the CHRF is increased by about 202%~456% compared with the regular circular foundation. The vertical bearing capacity and moment bearing capacity of the CHRF are approximately 5.1~7.9 and 1.36 time those of the regular circular foundation, respectively. In addition, it was also found that the ultimate horizontal bearing capacity of the CHRF decreases with increasing the aspect ratio (the ratio of the foundation top plate to the foundation height). On the contrary, the vertical and moment bearing capacities were found to increase with the increase of the aspect ratio. The effects of the scale on the bearing capacities of the CHRF were also investigated. It was found that the normalized horizontal bearing capacity and the vertical bearing capacity increase with the increase of the scale; however, the scale has little effect on the normalized moment bearing capacity of the CHRF.