基于黄河冲洪积地层试桩试验优化 桩基承载力设计的研究

Study on design method of pile foundation bearing capacity based on pile test in the Yellow River alluvial and pluvial formation

摘要:

以山东东营某工程为例，基于黄河冲洪积地层试桩试验成果，对试桩试验、试桩单桩极限承载力实测值与预估值相差较大（6.36%～20.19%）的原因进行分析。建立在相同桩顶标高（-5.7 m）条件下单桩极限承载力实测平均值与桩底标高（可以换算成桩长）的关系曲线，对工程桩桩基承载力设计方法进行优化。根据桩基检测结果，优化后的工程桩在相同桩长、桩径条件下单桩极限承载力实测值与预估值承载力相比提高约10%，达到发掘地质条件的潜力、减少桩数、节省工程造价的目的。相关试验方法、优化桩基承载力设计的方法可为类似地质条件的工程设计及建立区域桩基承载力数据库提供借鉴。

关键词:黄河冲洪积地层;钻孔灌注桩;桩基承载力

Abstract:

Taking a project in Dongying as an example, based on the test results of pile test in the Yellow River flood alluvial formation, the relation curve between the measured average value of the ultimate bearing capacity of single pile and the height of the pile bottom (which can be converted into pile length) under the condition of the same pile top elevation (-5.7m) is set up. The difference between the test pile test and the measured value of the ultimate bearing capacity of the single pile is quite different from the predicted value. The reasons and the optimal design method of pile foundation bearing capacity are introduced. According to the test results of the pile foundation, the measured value of the ultimate bearing capacity of the single pile under the same length and diameter of the pile is about 10% compared with the predicted bearing capacity, which can achieve the potential of excavating the geological conditions, reducing the number of piles and saving the cost of the project. Relevant test methods and methods of optimizing pile bearing capacity design can provide reference for engineering design under similar geological conditions and the establishment of regional pile bearing capacity database.

Key words:Flood alluvial strata in the Yellow River;Test pile test; Measured value of bearing capacity of pile foundation;optimization