大直径环型桩承载特性模型实验研究

Model Experimental Study on the Load-Bearing Characteristics of Large Diameter Circular Pile

大直径环型桩因其中部空心的特征,具有节省混凝土用料、控制成本和工程质量等优点。但其承载特性和安全性能仍处于尚不完全明确的状态,通过缩尺静载模型试验,并引入参数厚径比K,在外部条件相同的情况下,将实心桩与不同内径的环型桩做了对比研究,结果表明:在厚径比K=0.2~1的范围内,环型桩与实心桩的桩身极限承载力最大相差20%,但承载力特征值和安全性足够。在极限承载力下,环型桩与实心桩的应力应变分布及发展规律近似,且轴应力均小于自身材料强度。证明环型桩在K=0.2~1的范围内既能保证足够的承载力,又能节省50%以上的混凝土用量。

Large diameter circular piles have the advantages of saving concrete materials,controlling costs,and improving engineering quality due to their hollow center.However,its bearing characteristics and safety performance are still not fully clear.Through scaled static load model tests and the introduction of the parameter thickness to diameter ratio K,a comparative study was conducted between solid piles and circular piles with different inner diameters under the same external conditions.The results show that within the range of thickness to diameter ratio K=0.2~1,the maximum difference in ultimate bearing capacity between circular piles and solid piles is 20%,but the characteristic values of bearing capacity and safety are sufficient.Under the ultimate bearing capacity,the stress-strain distribution and development law of circular piles and solid piles are similar,and the axial stress is less than the strength of the material itself.It is proved that circular piles can ensure sufficient bearing capacity within the range of K=0.2~1,while also saving more than 50%of concrete usage.