PHYSICAL MODEL STUDY ON DAM BREAK FLOOD WAVE PROPAGATION AROUND TRIANGLE PYRAMIDE SHAPE BUILDING

• Main Author: NINGSIH (NIM : 25015019), RATNA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30251
• Institution: Institut Teknologi Bandung

<p align="justify"> Indonesia is an archipelago country surrounded by the sea and also with a very large population. Against this background, the availability of fresh water is one of the main problems in its development program. Therefore, Indonesia needs the right and proper infrastructure to guarantee the water supply needs throughout the year. One alternative water infrastructure is situ / embung. Because of the benefits, there are many sites / buffers built or planned to be built in Indonesia. Problems arise when there is a dam break or the so-called collapsed situ / embung that would cause a disaster. Events of the embankment collapse may invariably cause floods that cause many of the surrounding buildings to be damaged and also result in massive damage and losses. <br /> <br /> To reduce the damage from dam disaster, mitigation certainly needs to be done. As a disaster mitigation material, it is necessary to model surface flow due to dam break to know the flow characteristics that occur. Therefore, a physical model was created in the laboratory to determine the parameters of flooding by dam break. It is a special theme in the manufacture of physical models of flood propagation due to this dam break is reduced flow to the speed, depth and energy after the flow is muffled using a diamond-shaped energy reducer. The flow due to a very tight dam break will be muted using a silencer placed in the location that is considered the greatest flow height and speed. It is expected that with such energy dampers, flow height and flow velocity can be predicted so as to reduce damaged power to settlements located in downstream dams or reservoirs. Thus can be seen special treatment on the physical model in connection with the influence of no energy damper building and with building damper a squareshaped building with a 45-degree angle energy in giving the biggest damping effect. <br /> <br /> The physical dam break model is built on an open channel, with a channel length of 10 meters and a width of 1 meter. The reservoir used is upstream and downstream. Building energy absorbers used in the form of rhombus made of wood with a diameter (10x10x40) cm. Flood flow is modeled as a flash flood due to mass movement of water in large quantities with the sudden opening of water gates. As the initial conditions, the door will be closed. Upstream of the door, given the initial conditions of water level (20 cm, 30 cm, and 40 cm), while downstream there is only one building of energy damper. In principle, the flow due to flash flood (dam break) will be modeled by suddenly opening the floodgates. <br /> <br /> In this physical model study, experiments conducted in the laboratory consist of two scenarios i.e. without buildings and one building. Parameters to be measured are water depth measured by piezometer and current velocity measured with current meter. <br /> <br /> The results obtained from the measurement of water depth in the unstructured scenario show that the flow has maximum water depth in the third second, while in one building indicates that the flow has maximum water depth at the fifth time. The water level began to decrease in the eleventh hour, due to the influence of time on the water discharge in the reservoir. The results obtained from current velocity measurements show that the effect of current velocity on scenarios without buildings and one building has begun to be seen from one second to the next. This is in because the sluice has just opened so that the flow is still large in the upstream channel, while downstream channel, the speed is still very small. The prolonged profile velocity of scenarios without buildings begins to increase at a distance of 2.45 m from the door, so that the building is positioned at that distance i.e. 2.45 m from the door, the building in that position is very influential because at the moment there is a building the speed turns to small. <br /> <br /> From the studies that have been conducted, the results of this study can be used to provide early warning of the occurrence of a disaster where if the victim has not had time to escape can take shelter in sturdy buildings and high places so as not exposed to bases due to energy that occurs. <p align="justify">