卷积神经网络与随机场分析桩梁基础承载力

Convolutional neural network and random field analysis for analyzing the bearing capacity of coupling beam pile foundation

摘要:

岩土体的参数在空间上随机分布,为能更好地反应实际工程地质条件,在桩基础承载力研究中考虑土体的不确定性,并建立具有重要工程价值的承载力预测模型,将基于随机场理论的岩土参数空间变异性引入桩梁基础的研究中,采用数值方法建立桩梁基础与群桩基础的二维随机有限元模型分析承载能力,并与模型试验结果验证。随后通过卷积神经网络建立土体参数随机场图像与基础极限承载力之间的模型进行承载力预测,并基于预测模型研究不同参数的影响。结果表明:考虑土体空间变异性的基础承载力与试验结果基本吻合,随机结果均高于确定性分析；随机场下桩梁基础与群桩基础的承载力均为正态分布；采用卷积神经网络建立的基础承载力预测模型精度较高,且可以用于参数分析,基础承载力随着土体参数的增加而增加,随变异系数的增加而下降。随机条件下,桩梁基础的承载力高于群桩基础,可以充分发挥土体强度并抵御参数不确定性带来的承载力损失。

Abstract:

The parameters of geotechnical are randomly distributed in space. To better reflect the actual engineering geological conditions, considering the uncertainty of soil in the study of foundation bearing capacity, establishing a bearing capacity prediction model holds significant engineering value. Incorporating spatial variability of geotechnical parameters based on random field theory into the study of coupling beam pile foundation, a two-dimensional random finite element model is established using numerical methods to analyze the bearing capacity of coupling beam pile foundation and pile foundation, validated against model test results. Subsequently, a convolutional neural network is employed to establish a model between the random field images of soil parameters and the ultimate bearing capacity of foundations for bearing capacity prediction, and the impact of different parameters is studied based on the prediction model. The results indicate that considering the spatial variability of soil, the foundation′s bearing capacity is in basic agreement with experimental results, with random results consistently higher than deterministic analysis. Under random conditions, both coupling beam pile and pile foundations exhibit normally distributed bearing capacities. The accuracy of the bearing capacity prediction model established using convolutional neural networks is high and can be utilized for parameter analysis. The bearing capacity of foundations increases with increasing soil parameters and decreases with increasing coefficient of variation. Under random conditions, the bearing capacity of coupling beam pile foundation is higher than that of pile foundation, effectively leveraging soil strength to withstand bearing capacity loss caused by parameter uncertainties.