KAJIAN KINERJA DINDING PENGARAH REMBESAN DAN TES PERMEABILITAS DIAFRAGMA WALL PADA HILIR BENDUNGAN TUGU

Abstract

On the inside of the dam, there is a seamless instrumentation. V-Notch is one of the
standard dam safety instruments used to measure water dam seepage discharge. The
porous soil and high permeability around the V-Notch cause water seepage to not
be directed properly to the V-Notch. If it is not directed properly then the erosion of
the reed or piping cannot be detected. So we need a construction design of the
barrier wall for collecting water seepage, namely the wall diaphragm wall. The
purpose of this research is to analyze the material, evaluate the performance, and
compare the diaphragm wall. The method used is falling head test, monitoring
observation well (OW), direct observation method when working. The results of the
downstream wall diaphragm material permeability test using the fall head test show
that the largest permeability coefficient value is 1.3 x 10-5cm/sec. where this value
has reached a low coefficient of permeability. Results Downstream wall diaphragm
performance based on groundwater level at OW.8 < from OW.7. Downstream
diaphragm wall or water seepage collection barrier can be said to work well. From
the analysis method, the diaphragm wall is easier to work than using the Clay heap
method. This is proven because the diaphragm wall method can be carried out in the
rainy season and dry season. From the time calculation analysis, it is known that it
is faster to use the diaphragm method with an estimated working time of 4 months 2
days using 1 tool. As for the estimated length of time working with Clay soil piles is
7.5 months using 1.5 tools. Based on the calculation of the cost of drilling plastic
concrete is more expensive than the Clay heap method. The cost of diaphragm wall
is Rp. 9,581,703,257.38. and the cost of Clay is Rp. 8,742,490,556.95.