The Urugan Dam is a construction used to hold and
accommodate water made from piles of soil and rocks. The Urugan Dam is built
through the process of stockpiling a number of materials in the form of gravel,
gravel, rocks, sand and soil which are formed with a certain slope and height
so that they can hinder or raise the water level in the upstream.
Tuff material is found in the
research area. Tuff is a volcanic rock composed of volcanic ash and other rock
fragments ejected from volcanoes. Tuff is often found around volcanic regions
and can have a variety of colors and textures, depending on its composition and
formation process. The results showed that the maximum
acceleration at ground level was greater than the maximum acceleration in rocks
at low acceleration and vice versa at high acceleration. For high acceleration,
low stiffness and nonlinearity of soft soils often cause the maximum
acceleration not to increase as much as that that occurs in bedrock. For the
acceleration or spectral response of the 145-year re-period operation based
earthquake is 0.252 g with a period (sec) of 0.1 and the spectral
response of the maximum design earthquake period of 10000 years is 1.1 with a
period (sec) of 0.1.
The analysis of the dynamic response of the Jlantah Dam shows the results
of the acceleration amplification at the top of the dam 1.5 times to the
acceleration at the base (based on the results of the adjustment of the
acceleration of the imperial valley earthquake to the 2022 Indonesia Earthquake
Hazard Source Map). The deformation that occurred at the Jlantah Dam when it
was shaken by the earthquake OBE and MDE conditions is included in the category
of the degree of damage to the top of the dam class "none" (the
decline / settlement that occurs at the top of the dam is less than 50%).
