In order to study the critical load position that causes cavities beneath the continuously reinforced concrete pavement( CRCP) slab under vehicle loading, the elliptical load is translated into the square load based...In order to study the critical load position that causes cavities beneath the continuously reinforced concrete pavement( CRCP) slab under vehicle loading, the elliptical load is translated into the square load based on the equivalence principle.The CRCP slab is analyzed to determine the cavity position beneath the slab under vehicle loading. The influences of cavity size on the CRCP slab's stress and vertical displacement are investigated. The study results showthat the formation of the cavity is unavoidable under traffic loading, and the cavity is located at the edge of the longitudinal crack and the slab corner.The cavity size exerts an obvious influence on the largest horizontal tensile stress and vertical displacement. The slab corner is the critical load position of the CRCP slab. The results can be used to assist the design of CRCP in avoiding cavities beneath slabs subject to vehicle loading.展开更多
Based on the equivalence principle of deflection and stress, the concentrated vehicle load which acts on the center of continuously reinforced concrete pavement (CRCP) is translated into the equivalent half-wave sin...Based on the equivalence principle of deflection and stress, the concentrated vehicle load which acts on the center of continuously reinforced concrete pavement (CRCP) is translated into the equivalent half-wave sine load by the Fourier transform. On the basis of this transform and the small deflection theory of elastic thin plates, the deflection and stress formulae of CRCP under the concentrated vehicle load with a hollow foundation are put forward. The sensitivity of parameters is analyzed. The results show that maximum deflection is directly proportional to the concentrated vehicle load and the slab width, and inversely proportional to the lateral bending stiffness and slab thickness. The effects of slab width and thickness are significant with regard to maximum deflection. Maximum stress is directly proportional to the concentrated vehicle load and the slab width as well as inversely proportional to slab thickness. The effect of slab thickness is significant with regard to maximum stress. According to the calculation results, the most effective measure to reduce maximum deflection and stress is to increase slab thickness.展开更多
灌区管理DSS是指灌区管理人员在人和计算机组成的系统中,以计算机为辅助工具完成灌区各种信息的分析、处理等工作,产生供比较的方案,帮助决策者进行问题识别,并达到灌区合理规划和决策,及时有效地利用资源,获得最大的期望经济效益的目...灌区管理DSS是指灌区管理人员在人和计算机组成的系统中,以计算机为辅助工具完成灌区各种信息的分析、处理等工作,产生供比较的方案,帮助决策者进行问题识别,并达到灌区合理规划和决策,及时有效地利用资源,获得最大的期望经济效益的目的。本文介绍了水库灌区管理决策支持系统(Decision Support System,DSS)的基本框架,探讨了数学模型、数据库、人机界面的解决方案及系统设计中应注意的问题。水库灌区管理DSS的开发研究对我国水利信息化具有重要意义。展开更多
基金The Science Foundation of Ministry of Transport of the People's Republic of China(No.200731822301-7)
文摘In order to study the critical load position that causes cavities beneath the continuously reinforced concrete pavement( CRCP) slab under vehicle loading, the elliptical load is translated into the square load based on the equivalence principle.The CRCP slab is analyzed to determine the cavity position beneath the slab under vehicle loading. The influences of cavity size on the CRCP slab's stress and vertical displacement are investigated. The study results showthat the formation of the cavity is unavoidable under traffic loading, and the cavity is located at the edge of the longitudinal crack and the slab corner.The cavity size exerts an obvious influence on the largest horizontal tensile stress and vertical displacement. The slab corner is the critical load position of the CRCP slab. The results can be used to assist the design of CRCP in avoiding cavities beneath slabs subject to vehicle loading.
基金The Science Foundation of Ministry of Transport of the People's Republic of China(No.200731822301-7)
文摘Based on the equivalence principle of deflection and stress, the concentrated vehicle load which acts on the center of continuously reinforced concrete pavement (CRCP) is translated into the equivalent half-wave sine load by the Fourier transform. On the basis of this transform and the small deflection theory of elastic thin plates, the deflection and stress formulae of CRCP under the concentrated vehicle load with a hollow foundation are put forward. The sensitivity of parameters is analyzed. The results show that maximum deflection is directly proportional to the concentrated vehicle load and the slab width, and inversely proportional to the lateral bending stiffness and slab thickness. The effects of slab width and thickness are significant with regard to maximum deflection. Maximum stress is directly proportional to the concentrated vehicle load and the slab width as well as inversely proportional to slab thickness. The effect of slab thickness is significant with regard to maximum stress. According to the calculation results, the most effective measure to reduce maximum deflection and stress is to increase slab thickness.
文摘灌区管理DSS是指灌区管理人员在人和计算机组成的系统中,以计算机为辅助工具完成灌区各种信息的分析、处理等工作,产生供比较的方案,帮助决策者进行问题识别,并达到灌区合理规划和决策,及时有效地利用资源,获得最大的期望经济效益的目的。本文介绍了水库灌区管理决策支持系统(Decision Support System,DSS)的基本框架,探讨了数学模型、数据库、人机界面的解决方案及系统设计中应注意的问题。水库灌区管理DSS的开发研究对我国水利信息化具有重要意义。