风电场单桩竖向极限承载力估算方法对比分析

Comparative Analysis of Estimation Methods for Vertical Ultimate Bearing Capacity of Single Pile in Wind Farm

单桩竖向极限承载力是风电场桩基设计的重要依据。JGJ 94-2008《建筑桩基技术规范》给出了混凝土预制桩单桩竖向极限承载力标准值的经验参数法和静力触探法两种估算方法。文章以平原风电场为例,详细阐述了在饱和软弱土中两种估算方法结果的差异,分析了差异性的原因,得出了双桥静探法获取地质数据和估算成果精确度高,且估算成果大于经验参数法,经验参数法估算结果误差较大且偏于保守,提出以双桥静探法作为估算单桩竖向极限承载力的主要方法,并建议根据地区静载荷试验验证和修正,使成果更符合当地实际。

The vertical ultimate bearing capacity of a single pile is an important basis for the design of pile foundations in wind farms.In JGJ-94-2008"Technical Code for Building Pile Foundations",two estimation methods are presented:the empirical parameter method and the static cone penetration method for the standard value of the vertical ultimate bearing capacity of a single precast concrete pile.Taking a plain wind farm as an example,the difference between the results estimated by the two methods in saturated soft soil is explained and the cause for the difference is analyzed,and the result is that the double-bridge static penetration method is more accurate in obtained geological data and estimation results and the estimation results are greater than that of the empirical parameter method;the empirical parameter method is of larger errors and its estimation results are more conservative.The double-bridge static penetration method is proposed as the main method for estimating the vertical ultimate bearing capacity of a single pile.The results shall be checked and modified to be in line with local practice.