复杂岩溶场地桥梁桩基选型探究与实践

Exploration and Practice on Selection of Bridge Pile Foundations in Complex Karst Sites

摘要:

石灰岩地区受岩性特征、地质构造、地下水作用等多因素影响，导致地下岩溶隐蔽性强、不规则、复杂多变，复杂岩溶不良地质条件对桥梁桩基产生不利影响。为解决复杂岩溶场地桥梁桩基选型的问题，结合场地详实地质条件和岩溶发育特征，通过对桩基承载性状、桩基成桩施工方式、桩基埋置深度等方面的探究和分析，提出了复杂岩溶区桩基埋置深度并非越深越好；另外部分复杂岩溶区地段完整持力层埋藏深度极大或者无连续完整的持力层，对于该特殊地质条件，可考虑进行人造持力层，即通过人为改造构筑连续持力层以满足桩基承载力。相关实践案例可作为复杂岩溶区桩基选型的参考。

Abstract:

Limestone regions are influenced by multiple factors such as lithological characteristics, geological structures and groundwater activity, resulting in strong concealment, irregularity and complex variability of underground karst. The adverse geological conditions of complex karst significantly impact the bridge pile foundations. To address the challenges of pile foundation selection in complex karst sites, combined with the detailed site geological conditions and the karst development characteristics, and through exploration and analysis on the bearing characters, piling construction methods and burial depth of pile foundation, it is proposed that the burial depth of pile foundations in complex karst areas is not necessarily the deeper the better. Additionally, in certain areas with extremely deep or discontinuous intact bearing strata, the artificial bearing layers can be considered by artificially constructing the continuous bearing strata to meet the bearing capacity of pile foundations. The relevant practical cases can serve as references for the selection of pile foundations in complex karst regions.