No abstract

For links in eccentrically braced frames (EBFs), today’s design codes requirement of the flange width-thickness ratio is strict on high-strength steels, which eliminate a number of rolled wide-flange shape from use in EBFs. For this reason, building models using ANSYS program and control procedures for the previous tests to verify the correctness, and then design the specimens. This paper applies unidirectional load and cyclic load on the finite element models respectively. Through the calculation of the inelastic rotation which the link beams reach after the relaxation of the flange width-thickness ratio, the paper analyses the influences on the performance of the three tapes of links by the flange width-thickness ratio.

Theory equations and specification equations are currently main methods to calculate wall rock pressure. These equations are created in certain backgrounds, and are applicable in certain ranges, not fit for deep-buried or large span tunnels. Analysis methods combined with actual project are used, and measured data are contrasted with the theoretical results. Common used calculation equations are discussed from the aspects including calculation accuracy, the relationship with buried depth and the relationship with span of underground structure. Revised calculating equation for wall rock pressure of deep-buried and large-span tunnel are put forward, and is proved to be better on the aspects above. It has significance in theory and practice.

Numerical simulation method was used to study the problems on critical anchorage length of bolts. 3-D calculation model was built by FLAC program. By numerical simulation calculations, the conclusion could be drawn: the frictional resistance contribution had nothing to do with drawing forces, and was relevant to the bond stiffness of anchor mortar. And comparative analysis results of one engineering example showed that the calculated values by the presented method agreed well with the measured data.