重载港区联锁块铺面结构设计技术

Considering the problems existed in the design method of interlocking block pavements for port road and stockpile pavements in China,including 1. the precision for container design loading is inadequate and lack of data support, 2. the mechanistic model for interlocking block pavements is too simple, and 3. the damage effects arising from all types of loading & transport vehicles on interlocking block pavements are difficult to consider comprehensively. Through statistical analysis of measured data, the standard values and partial factor for container leg loadings in accordance with the national container weights distribution is proposed. A three dimensional mechanistic model for interlocking block pavements considering the effects of interlock and friction from adjacent blocks is established, by paving a full-scale interlocking block pavements the model is then validated and calibrated. Thereinafter, by using the finite element method, the loading spreading capacity of the interlocking block pavements is thoroughly analyzed, the influences of block size and friction on the structural behaviours of the pavements are also discussed. The characteristics of loading & transport vehicles are sequentialy summarized, categorized and graded, a method to calculating the equivelant loading for loading & transport vehicles relevant to the failure mode of interlocking block pavements is brought forward, and the equivelant coefficients for each type of commonly used loading & transport vehicles are given. On the basis achieved above, a design method as of interlocking block pavements for heavy duty ports is eventullay put forward. The research can be helpful to understand the failure mechnism and structural behaviours of interlocking block pavements, and develope the key design techniques of interlocking block pavements for heavy duty ports.

针对我国现行港口堆场、道路的联锁块铺面设计方法中存在的三大问题：1.集装箱荷载设计值的精度不足和依据缺失；2.联锁块面层结构的力学模型过于简化；3.无法综合考虑各类装运荷载对铺面结构损坏效应。通过对实测数据的统计分析，提出符合我国集装箱箱重分布规律的集装箱箱角荷载的设计标准值和分项系数。建立考虑块体间嵌挤和摩阻的联锁块铺面结构三维有限元法模型，通过足尺试验对模型进行验证和标定，进而，系统分析联锁块铺面结构的荷载扩散能力，联锁块尺寸、块体间嵌挤和摩阻的影响。对港区装运机械的荷载特征进行归纳、分类、分级，提出与铺面结构损坏类型相对应的装运机械当量荷载方法，给出各类常用装运机械的当量系数。在此基础上，建立重载港区联锁块铺面结构设计方法。研究有助于弄清联锁块铺面结构的破坏机理和规律，攻克重载港区联锁块铺面结构设计的关键技术。

联锁块铺面具有很多独特的优点，我国现行《港口道路、堆场铺面设计与施工规范》(JTJ 296-96)颁布已有20多年，其中存在着不能满足港区荷载重型化趋势要求、联锁块铺面结构力学模型与实际状况有较大差异和缺乏简便实用的港区流动机械荷载的处理方法等突出问题，亟待完善和改进。.本项目研究搜集、整理了现阶段港区流动机械荷载和集装箱荷载情况；对现行流动机械轮、轴荷载分级进行调整；分析了集装箱重箱的箱重分布规律；给出了集装箱荷载设计标准值的计算公式。.根据联锁块铺面结构的主要破坏形式和结构响应，选择土基顶面压应变作为柔性基层联锁块铺面的结构设计指标，基层层底弯拉应力为刚性、半刚性基层联锁块铺面的结构设计指标。对铺面材料的强度、疲劳方法、弹性模量和土基回弹模量等铺面设计参数进行了明确的规定。.建立了联锁块铺面三维实体模型，其中，联锁块块间设置各向异性的夹层单元，夹层与联锁块有初压应力且受压连续、受拉脱开；基于路表回弹弯沉、基层层底弯拉应力和土基顶面弯拉应力等效原则，将联锁块层等效为一弹性均匀层。总结了不同铺砌方法，接缝夹层模量和初压应力情况下的联锁块层等效模量的变化规律，给出了回归公式。先后进行了二次足尺联锁块铺面结构承载试验，第一次采用异形联锁块，第二次采用矩形块联锁块；依据两次室内足尺试验结果，对三维有限元模型中的结构参数和边缘约束条件进行标定，结合工程经验给出了不同条件下联锁块层等效模量推荐值。.归纳提出了港口常用各种型号的叉车、正面吊、轮胎式和汽车式起重机、跨运车、龙门吊、集装箱拖挂车、平板车等流动机械在不同铺面结构、不同设计指标条件下的当量单轮荷载系数的回归式。实现了港口诸多荷载的简便且精确的当量化。.综上成果，建立一套完备的重载港区联锁块铺面结构设计方法。该设计方法及参数已被中华人民共和国行业标准《港口道路与堆场设计规范》(JTS168-2017)采用。