冲击碾压动荷载下水泥混凝土路面结构的力学行为_胡昌斌

第8卷　第4期2008年8月

交通运输工程学报

Journal of T raffic and Transportation Engineering

Vo l .8　No .4Aug .2008

收稿日期:2008-01-02基金项目:福建省自然科学基金项目(E0410017);福建省高等学校新世纪优秀人才计划项目(003387)作者简介:胡昌斌(1974-),男,湖北孝感人,福州大学副教授,工学博士,博士后,从事道路工程与土动力学研究。

文章编号:1671-1637(2008)04-0040-07

冲击碾压动荷载下水泥混凝土路面结构的力学行为

胡昌斌,阙　云

(福州大学土木工程学院,福建福州　350002)

摘　要:为了揭示冲击碾压动荷载下水泥混凝土路面结构的力学行为,基于动力三维有限元分析方

法,考虑材料的弹塑性,拟定纵横板边、板中及板角4种典型荷载位置,在四楞冲击压路机冲击碾压水泥混凝土路面时,分析了路面各层结构的受力和变形特征。研究发现,各工况下混凝土板底部承受纵、横向弯拉应力是旧面板破裂的主要原因,基层与旧面板一起处于双向弯拉状态,土基三向受压,不同工况存在不同的有效影响深度。冲击碾压板角时,路面板竖向位移最大,影响深度最深;而冲击板中位置时,板竖向位移最小,分布最均匀,此时板体以纵向弯拉为主,易形成横向裂缝;当冲击纵向板边时,板体以横向弯拉为主,易形成纵向裂缝。可见,路面破碎效果是地基刚度、冲击能量与冲击位置的综合函数,建议基于具体路况选择相应的施工方案。关键词:路面工程;水泥混凝土路面;冲击碾压;有限元分析;力学行为中图分类号:U416.216 文献标识码:A

Mechanical behaviors of cement concrete pavement

structure under impact rolling load

H U Chang -bin ,Q UE Yun

(Scho ol of Civil Engineering ,Fuzhou U nive rsity ,Fuzho u 350002,Fujian ,China )

A bstract :In order to explain the mechanical behavio rs of cement concrete pavement structure

under im pact rolling load ,four ty pical loading positions were considered such as slab long itudinal side ,slab transverse side ,slab corner and slab center ,the stress and deformation characteristics of pavement structures unde r the impact load of quadrilateral impact roller w ere studied based on 3D elastic -plastic dynamic finite element metho d .Analy sis result indicates that the main reaso ns of old cement co ncrete pavement cracking in diffe rent cases are that the bo ttom of cem ent co ncrete pavement bears longitudinal flexural -tensile stress and transverse flexural -tensile stress ,bo th base course and o ld slab appear flexural -tensile state in tw o directio ns ,w hile subg rade is in three dimension compressive stage ,and the effective influence depths are diffe rent in diffe rent cases .The vertical displacements of slab and influence depths are maxim um w hen the load locates at slab co rner ,w hile the vertical displacements of slab are minim um and uniform w hen the load locates at slab cente r .Pavement slab is in longitudinal bending stage and easily fo rm s transverse cracks w hen the load locates at slab center ,w hile pav em ent slab is in transver se bending stage and easily fo rms longitudinal cracks w hen the lo ad locates at slab side .So the cracking effect is a sy nthetic function of foundatio n stiffness ,impact energy and impact lo cation ,it is reasonable that constructing scheme is cho sen according to different ro ad conditio ns .2tabs ,10fig s ,10refs .Key words :pavement engineering ;cement concrete pavement ;impact ro lling ;finite elem ent