ECC桥面连续构造设计参数敏感性有限元分析

Finite Element Analysis of Design Parameter Sensitivity of ECC Bridge Deck Continuous Structure

摘要:

为研究超高韧性水泥基复合材料（ECC）桥面连续构造的力学性能，利用ABAQUS软件构建全桥有限元模型，分别以脱黏区长度、厚度及纵向配筋率为设计参数，开展车道荷载、桥梁整体降温和支座不均匀沉降三种荷载作用下的ECC桥面连续构造力学分析。结果表明：增加脱黏区长度能有效降低ECC桥面连续构造在荷载作用下的力学响应，当脱黏区长度为相邻两跨主梁长度之和的5%时，即能满足构造受力和变形的要求；ECC桥面连续构造与桥面铺装厚度相当时，最不利荷载组合作用下应力和应变最小；纵向配筋率对ECC桥面连续构造的受力影响较小。ECC桥面连续构造在三种荷载作用下的最大拉应力为3.58 MPa，达到ECC抗拉强度的74%，已充分发挥ECC的应变硬化特征，能有效防止构造受拉开裂。

Abstract:

In order to study the mechanical properties of the continuous structure of bridge deck with engineered cementitious composites (ECC), Abaqus software is used to establish the finite element model of the whole bridge. The length, thickness and longitudinal reinforcement ratio of the debonding zone are taken respectively as the design parameters to carry out the continuous structural mechanics analysis on ECC bridge deck under three kinds of loads, such as lane load, overall bridge cooling and uneven settlement of supports. The results show that increasing the length of the debonding zone can effectively reduce the mechanical response of ECC deck continuous structure under load. When the length of the debonding zone is 5% of the sum of the length of the two adjacent girders, the requirements of structural stress and deformation can be met. Under the action of the most unfavorable load combination, the stress and strain of ECC bridge deck are the least when the continuous structure is the same thickness as the bridge deck pavement. The longitudinal reinforcement ratio has little influence on the stress of ECC bridge deck continuous structure. The maximum tensile stress of ECC bridge deck continuous structure under three kinds of loads is 3.58 MPa, which is 74% of the ECC tensile strength.It has fully exploited the strain hardening characteristics of ECC, and can effectively prevent the structure from cracking due to tension.