Thesis (M. Arch.)--University of Hong Kong, 2004. / Includes special report study entitled : Sustainable way of architectural conservation in urban regeneration. Also available in print.

This thesis presents the investigation of the behaviour of continuous arches on elastic piers about which little is currently known. A series of studies were made to indicate the effects of pier dimensions on extreme fiber stresses at a number of critical sections of arches. Such results are of particular interest to the bridge designer. Six numerical examples of symmetrical arch systems have been solved, using an interesting variation of the force distribution method of the late Prof. Hardy Cross. The relative proportions of the system were based primarily upon aesthetic considerations. In the six structures which were investigated two systems of arches and piers, called I and II, were considered. Each system has five spans. The variable span lengths are the same in each system. The arches in each were selected from Whitney's paper and are linear arches for dead load only. In System I the arch ribs are lighter and flatter than in System II, and the piers are more flexible. In each system the variation of span lengths and arch rises are such so that there is no unbalanced dead load horizontal thrust on the piers. In both systems all piers are of single equal batter. Three different heights of pier 40', 60', and 80' were investigated in each system. Figs. 1, 2 and 3 clarify the foregoing while Tables 1 and 2 give the properties of the elements making up each system. In System I twenty influence lines for upper, lower, right, and left kern moments at springings, crowns, and pier tops were constructed. In System II "portions" of sixteen influence lines for upper and lower kern moment at springings and crowns sufficient to establish the trend of alteration of proportions were constructed. The large number of variables involved in the design of such indeterminate structures as continuous arch systems makes it inadvisable to draw too definite conclusions, but some results of studies obviously indicate that : (1) All controlling L.L. fiber stresses are greater than those in fixed ended arches and increase as the height of piers increases, but the maximum D.L. + L.L. fiber stresses do not exhibit this characteristic as might be expected but depend, of course, upon the ratio of dead load to live load as well as upon the proportions of the structure. (2) It would appear that the analysis may be confined to three spans for arches and two spans for piers, save in the case of a long centre span combined with very flexible piers. In such a case the complete structure must be involved in the analysis. (3) The effect of rotation of the pier tops on L.L. stresses at crowns is small and almost independent of pier height, whereas the effect on L.L. stresses at springings is somewhat greater and increases slowly as the height of piers increases. The effect of translation of the pier tops on L.L. stresses at springings and crowns is usually the greatest and increases rapidly as the height of piers increases. The results presented herein are, of course, true only for this particular type of system, but the author feels that the system chosen is more representative of a structure which might be constructed than are the typical three or four equal span systems of the text book variety with which some writers, more concerned with simplicity than reality, have dealt. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

No description available.

Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 163-167).

Thesis (M.Phil.)--University of Hong Kong, 2001. / Includes bibliographical references. Also available in print.

This thesis presents a review of the reported research on local sand-bed scour around bridge piers, describes the mechanics of local scour with particular reference to the horseshoe vortex, describes experiments on the effect of the vertical velocity distribution of the approach flow on local scour, and reports the results of these experiments. The review of the previous research on local scour shows that the pier size is the most important parameter affecting the equilibrium depth of local scour, while the pier shape is of secondary importance. Two flow parameters are found to be important; the flow velocity and the flow depth, although their relative importance depends on the regime of the flow being considered. The primary scouring agent is seen to be the horseshoe vortex system, which is a system of linked vortices that arises out of the vorticity always present in shear flows, due to the interaction of the pier and the flow. The experiments that were done consisted of observations and measurements of vertical velocity distributions, scour depths, and vortex patterns, for a circular cylinder in a laboratory flume. These experiments showed that the vertical velocity distribution of the boundary layer flow approaching the pier affects the structure of the horseshoe vortex system and the equilibrium depth of scour at the pier nose. The Thesis concludes with a Summary and Conclusions, including recommendations for further research. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: Jacob L. Bowman, Dept. of Entomology & Wildlife Ecology. Includes bibliographical references.

Not available / text

No description available.