Tie Bars Research Articles

Design of Tie Bars in Portland Cement Concrete Pavement considering Nonlinear Temperature Variations

Tie bar design at longitudinal construction joints in portland cement concrete pavement is based on the so-called subgrade drag theory. According to this theory, the required maximum spacing between tie bars is inversely proportional to the widths of the lanes that are tied together. As the number of lanes increases to accommodate greater traffic demand, tie bar spacing decreases. In a recent IH-10 project in Houston, Texas, the width of pavement lanes tied together was great enough to require 30-cm (1-ft) tie bar spacing. In Texas Department of Transportation design standards for continuously reinforced concrete pavement, the same spacing is required for both tie bars and transverse steel. The use of 30-cm spacing for both tie bars and transverse steel results in a substantial increase in the cost of the project. The subgrade drag theory assumes uniform temperature distribution through the concrete slab depth and no curling effect is incorporated. This assumption needs reconsideration. Field testing was conducted to investigate slab behavior and to develop more rational designs for tie bars and transverse steel. Concrete displacement gauges were installed at the free edge of the concrete slab to measure transverse horizontal as well as vertical displacements. Steel strain gauges were installed at different locations in tie bars. The concrete slab showed curling behavior; the stresses in tie bars clearly demonstrated the effects of curling. Theoretical analysis was conducted, and the results verified the field data. A new design method was proposed for tie bars.

Optimum topology design for the stationary platen of a plastic injection machine

Tie bars are key components of a plastic injection machine. They very easily fatigue in periodically long term operations due to the bending moment transferred to them by the bending of the stationary platen. This problem can be easily overcome by reducing the deflection of the stationary platen through topology optimization of the platen structure by applying a cost or weight constraint. In this paper, the self-organization method was introduced to optimize the topology of the stationary platen. Topology design optimizes material allocation, i.e. strengthening locations of high loads and minimizing material usage at other locations. By applying this method to the stationary platen design, the deflection of the platen could be reduced, which correspondingly reduces the bending load of the tie bars and thus extending their operating life.

SRC造柱梁接合部帯筋に重ね継手を用いる工法の開発とその適用条件

SRC造柱梁接合部帯筋に重ね継手を用いる工法の開発とその適用条件

Design of Tie Bars for Large Drilled Pier Foundations

First Name is required invalid characters Last Name is required invalid characters Email Address is required Invalid Email Address Invalid Email Address

35) 軸方向力による材長の變化を考慮すべき部材を含むラーメンの解法

35) 軸方向力による材長の變化を考慮すべき部材を含むラーメンの解法