基于改进遗传算法的住宅楼桩基坑支护结构设计方法

The design method of pile foundation pit supporting structure of residential building based on improved genetic algorithm

针对目前使用的一桩两用、复杂双排灌注桩的基坑支护结构设计方法,受到基坑环境不确定性及复杂性影响,导致数值模拟结果与理想数值不一致,为了解决该问题,提出了基于改进遗传算法的住宅楼桩基坑支护结构设计方法。以某房建工程项目作为研究对象,结合改进遗传算法,构建数学模型。从桩的最大弯矩、桩嵌入土体的深度两个方面考虑数学模型的约束条件,采用惩罚函数法来处理约束问题。依据住宅基坑周围环境,选择基坑段面,并进行图层概化。在设计坑中坑钢板桩基坑支护结构,有效控制坑中坑变形。另外通过高压旋喷桩方式,基坑支护结构的侧壁设置一道不透水的止水帷幕,防止上层滞水流入基坑。由仿真实验结果可知,该方法对于桩顶水平位移,与理想数值最大误差为0.05 mm;对于桩体下降深度,与理想数值最大误差为0.1 mm;对于地表沉降量,与理想数值一致,误差为0 mm,对施工来说更加安全。

In view of the current design method of foundation pit support structure with one pile for two purposes and complex double-row cast-in-place piles, the numerical simulation results are inconsistent with the ideal values due to the uncertainty and complexity of the foundation pit environment. In order to solve this problem, a design method of foundation pit support structure with piles for residential buildings based on improved genetic algorithm is proposed. Taking a real estate construction project as the research object, combined with improved genetic algorithm, the mathematical model is constructed. Considering the constraint conditions of the mathematical model from the maximum moment of the pile and the depth of the pile embedded in the soil, the penalty function method is used to deal with the constraint problem. According to the surrounding environment of the residential foundation pit, select the foundation pit section and generalize the layer. In the design of pit in pit steel sheet pile foundation pit support structure, effectively control pit in pit deformation. In addition, through high-pressure jet grouting pile, an impermeable water stop curtain is set on the side wall of the foundation pit support structure to prevent the upper stagnant water from flowing into the foundation pit. According to the simulation results, the maximum error between the method and the ideal value for the horizontal displacement of the pile top is 0.05 mm;For the falling depth of pile, the maximum error from the ideal value is 0.1 mm;For the surface settlement, it is consistent with the ideal value, with an error of 0 mm, which is safer for construction.