Numerical modelling for predicting corrosion initiation life of reinforced concrete square piles under reverse-seepage pressure

Square piles of reinforced concrete(RC)in marine environments are susceptible to chloride-inducedcorrosion.A novel reverse-seepage technique(RST)is applied to square piles to block the intrusion of chlorides.Thisresearch introduces a computational model designed to predict the lifespan of corrosion initiation in reinforced concretesquare piles when applied reverse-seepage pressure.The model considers the impacts of chloride binding and the tripletime-dependence property among the permeability,the corrected surface chloride concentration,and the diffusioncoefficient.The proposed numerical model is solved using the alternating direction implicit(ADI)approach,and itsaccuracy and reliability are evaluated by contrasting the computational outcomes with the analytical solution andexperimental results.Furthermore,the primary factors contributing to the corrosion of reinforced concrete square pilesare analyzed.The results indicate that applying RST can decrease the chloride penetration depth and prolong the lifespanof corrosion initiation in square piles.The water-cement ratio and reverse seepage pressure are the most influentialfactors.A water pressure of 0.4 MPa can double the life of concrete,and the durable life of concrete with a water-cementratio of 0.3 can reach 100 years.

“窄路密网”理念下城市道路横断面多样性设计研究

近年来,基于“窄路密网”理念的道路规划在我国城市建设中得到逐步应用,道路红线宽度的缩小,直接影响道路横断面的设计,对于支路,横断面设计方案越来越单一。基于此,文章在分析“窄路密网”道路规划格局特点的基础上,对支路的横断面布局多样性进行分析比对,结合工程实际,对沿线不同地块性质、不同交通需求的道路横断面设计方案进行探究,通过增加断面多样性,为类似道路设计方案提供可借鉴的经验。