FINAL TEST
Non-Destructive Test
Name
: Bangun Dwika Saputra (巴翰舒)
Student ID : A10230011
1. Describe the result of ERT Test.
Electrical resistivity is a geophysical method in which an electrical current is injected
into the ground through steel electrodes in an attempt to measure the electrical
properties of the subsurface.
Figure 1 Soil Resistivity Properties (Palacky,1987)
1.1
Trial 1 ERT with WS Method
This trial use WS method, with electrode spacing 0.50 m. this below attached the
electrical properties of soil as approach to define the type of soil. The depth of this
test is 0.00 m – 2.75 m, and the length of this trial is 13.5 m. From the test result
we can get :
1) Green Zone, In this trial line the dominan soil type is has resistivity + 128 ohmm, that’s mean this type have medium resistivity (100<p<1000), from resistivity
approach, this zone is dominant of silty clay, where ground water not so
difficult to obtain.
2) Blue Zone, blue zone that’s mean have low resistivity (p<100). Blue zone has
found at 7.5m-8m and 8.5m-9.5m with depth layer is 0.00-0.69m, from this
approach we can conclude that this soil zone contain water in surface soil. This
area which have low resistivity meaning high corrosive soil, corrossion
increase as resistivity decreases.
3) Orange Zone, which have resistivity range + 974 ohm-m that’s mean this type
have medium resistivity (100<p<1000), from resistivity approach this zone is
dominant sandstone, which is the porosity ratio of this soil is low.
4) Red Zone, in this test result red zone located between 8.0m-8.5m, this zone
have resistivity 974-7382 ohm-m, that’s mean this zone have high resistivity.
From this indicators we can conclude in this zone have rock or something
material which is have low electrical conductivity, because the location of this
zone is in the surface area (0.00m-0.69m) so that’s not indicate bed rock layer,
but just a something stuff which have high resistivity properties buried in surface
of soil
2. Describe the result of High Performance Temeperature Test
BH-3
Temperature (oC)
23.410023.415023.420023.425023.430023.435023.440023.445023.4500
22
22.5
Depth (m)
23
23.5
24
24.5
25
From the measurement, we can get:
1. Data sample taken on Bore Hole (BH) 3, data measure every 0.05 m, and the
accuration is 0.0001, so that’s why the name of this measurement is High
Performance Temperature Logger
2. The highest temperature for BH-3 was 24.6962 ⁰C at depth 4.07 m
3. Ground Water Level at depth 23.49 m, the indicator is at depth 23.09 m
temperature is 23.4325 ⁰C, then the temperature change significanly from
23.14 m – 24.19 m, the temperature going down to 23.4241 ⁰C, so the change
of temperature indicates the ground water flow.
Conclussion :
The location of ground water table from depth 23.49 m, so when we will do
preventive action to avoid ground water problem affect to the construction such us
piping, or landslide, if we do dewatering or soil improvement like grouting we know
the right location of ground water table with temperature apporachment. The change
of water temperature indicate the location of ground water table and the
direction of ground water flow.