（1 同济大学建筑工程系， 上海 200092； 2 上海风畅土木工程技术有限公司， 上海 201799）

［摘要］由于运输条件的限制，某些位于偏远山区的风电项目无法采用商品混凝土，而现场搅拌的混凝土因质量难以达标,出现了强度过低导致的基础环基础开裂、压碎和刚度降低等现象。针对上述问题，对基础环基础提出了一种环向预应力加固方案，即在柱墩侧壁设置钢绞线，通过施加环向预应力减小基础柱墩的受拉区域，使柱墩处于三向受压状态，充分发挥混凝土受压性能良好的特点，限制基础混凝土裂缝的进一步发展。并以某风力发电塔基础为例，建立精细化有限元模型，分析了混凝土未达到设计强度的基础在加固前后的应力状态和应变分布。分析结果表明，环向预应力加固方案能够有效减小基础裂缝宽度和因受拉、压产生的塑性区域，显著提高基础刚度，加固效果显著，对同类工程的加固处理有一定参考价值。

［关键词］风电机组； 基础环基础； 混凝土低强； 环向预应力； 有限元方法

中图分类号：TU470+.3文献标识码：A文章编号：1002-848X(2019)10-0119-06

Research on strengthening measure of low-strength concrete for embedded-ring foundation of wind turbine tower

Chen Junling1， Zhang Youchen1， Feng Youquan2

(1 Department of Structural Engineering， Tongji University， Shanghai 200092， China；2 Shanghai Fengchang Civil Engineering Technology Co.， Ltd.， Shanghai 201799， China)

Abstract:Due to the limitation of transportation conditions, some wind power projects located in remote mountainous areas cannot use commercial concrete, while the concrete mixing on site is difficult to meet the quality standards, resulting in cracking, and crushing and stiffness reduction of embedded-ring foundation caused by low strength. In view of the above problems, a reinforcing scheme was put forward using embedded-ring foundation with circular prestress, that is, setting steel strands on the side wall of the pier, reducing the tension area of the pier by applying circular prestress. This can make the pier in a three-dimensional compression state, giving full play to the good compressive performance of concrete, and restricting the further development of concrete cracks in the foundation. Taking the foundation of a wind power tower as an example, a refined finite element model was established, and the stress state and strain distribution of the foundation before and after strengthening were analyzed. The analysis results show that the circular prestress reinforcement scheme can effectively reduce the crack width of the foundation and the plastic area under tension and compression, significantly improve the foundation stiffness, and the reinforcement effect is remarkable, which has a certain reference value for the reinforcement treatment of similar projects.

Keywords:wind turbine tower; embedded-ring foundation; low-strength concrete; circular prestress; finite element method

作者简介：陈俊岭，博士，教授，博士生导师，一级注册结构工程师，Email：chenjl@tongji.edu.cn。