Experiment On Semi-circular Arch 6d2l2e

TITLE : EXPERIMENT ON SEMI-CIRCULAR ARCH 1.1 INTRODUCTION The main advantage of an arch has over a beam, is that it can carry a much larger load. History arches wee important because they could be constructed using small, easy carry blocks of brick or stone rather than using massive, monolithic stone beam or lentil. Romans used the semi-circular arch in bridges, aqueducts and in large-scale architecture. In most cases they did not use mortar, relying simply on the precision of their stone finish. When an arch is loaded by gravity forces, the pressure acts downward on the arch and has the effect of compressing it together instead of pulling it apart. In this laboratory activity students will be exposed to the apparatus and the procedures to carry out experiment on two-hinged and three-hinged arches. 1.2 OBJECTIVE The objective of the experiment is:  To determine the relationship between applied load and the horizontal thrust at the s of a two-hinged and a three-hinged arches.  To explore the relationship between the loads and the horizontal reaction force in threepinned arch.  To determine the horizontal thrust in a three hinged arch for a given system of loads experimentally and the same with calculated values.

1.3 THEORETICAL BACKGROUND Arches have a diverse range of applications in bridges, arched dams and in industrial, commercial and recreational buildings. An arch is ed by abutments. The heels and crown are the lowest and highest points of the arch, respectively; s may be rolled, pinned, or fixed. Horizontal distance between two heels is span L, a vertical distance between heels line and crown is rise r. (Source: Theory of Arched Structures by Igor A. Karnovsky)

Three-hinged semi-circular arch

1.4 PROBLEM STATEMENT to determine the relationship between applied load and the horizontal thrust at the s of a threehinged arches. 2 2.1 APPARATUS I. frame II. Three hinge arch assembly III. A simple IV. A roller V. A set of weights 2.2 PROCEDURE i. The load cell was connected to the digital indicator ii. The indicator was switched on. For stability of the reading the indicator must be switch on 10 minutes before taking readings. iii. The load hanger was placed at the location where the load is to be applied. iv. The indicator reading was noted. If it is not zero press the tare button. v. A load was placed on the load hanger. vi. The indicator reading was recorded. This represents the horizontal reaction of the pinned . vii. The load on the load hanger was increased and the horizontal reaction was recorded. viii.Step 7 was repeated for another 4 load increments. ix. The result was tabulated. x. The experiment was repeated to get another set of readings.