Sains Malaysiana 43(10)(2014):
1477–1484
Rainfall
Infiltration through Unsaturated Layered Soil Column
(Penyusupan Air Hujan melalui Tanah Tak Tepu pada Tiang
Tanah)
ANIZA IBRAHIM1,2, MUHAMMAD MUKHLISIN1,3*
& OTHMAN JAAFAR1
1Department of Civil
and Structural Engineering, Universiti Kebangsaan Malaysia
43600 Bangi, Selangor, Malaysia
2Department of Civil
Engineering, Faculty of Engineering, Universiti Pertahanan Nasional Malaysia, Kem
Sungai Besi, 57000 Kuala Lumpur, Malaysia
3Department of Civil Engineering,
Polytechnic Negeri Semarang, Indonesia
Diserahkan: 18 Jun 2012/Diterima: 18 Februari 2014
ABSTRACT
Infiltration caused by rainfall will lead to the changes of
moisture content and soil pore water pressure or matric suction of the soil.
These changes indicate the behavior of the soil especially during wetting and
drying process. This paper presents the experimental test result of rain water
infiltration into soil column for two samples of soils. The main objectives
were to study the effect of rainfall intensity and duration of soil
infiltration process for the forest soil and to compare its result to the gravelly
sand. Infiltration experimental in this study involved three main components;
water supply system, soil column and instrumentations, including percolation
collection system. This study uses two types of tensiometers; 5 and 10 cm long.
The results of TDR and tensiometers which were used to
obtained moisture content and matric suction, respectively, shows that the
system was successfully developed. For the forest soil, the result showed that
moisture content of the top section is higher compared with the other sections.
On the other hand, for gravelly sand, the moisture content in middle section is
higher compared with the top and bottom section of the soil. Meanwhile, matric
suction for both soils dropped during rainfall and gradually increases towards
drying process. Other than that the comparison of soil matric suction between 5
and 10 cm tensiometers shows significant results for gravelly sand compared to
forest soil.
Keywords: Infiltration; matric suction; soil column; soil moisture
ABSTRAK
Penyusupan yang disebabkan oleh hujan akan merubah kandungan lembapan dan tekanan air liang tanah. Perubahan ini adalah
merupakan penanda kepada sifat tanah terutamanya semasa proses pembasahan dan
pengeringan daripada hujan yang turun. Kertas kerja ini memaparkan
keputusan yang dicapai daripada uji kaji makmal berdasarkan ujian air hujan
yang menyusup ke dalam dua sampel tanah. Objektif
utama kajian ini adalah untuk mengkaji kesan daripada keamatan dan tempoh air
hujan untuk sampel tanah dari kampus dan dibandingkan dengan sampel pasir
berkerikil. Ujian penyusupan ini terbahagi kepada tiga
komponen; sistem bekalan air, tiang tanah dan instrumentasi dan juga sistem
pengaliran keluar air. Kajian ini menggunakan dua jenis tensiometer; 5 dan 10 cm panjang. Keputusan yang diperoleh menunjukkan
tanah dari kampus mempunyai kandungan lembapan yang tinggi pada bahagian atas
tiang dibandingkan dengan bahagian yang lain. Manakala pasir
berkerikil pula, tanah pada bahagian tengah tiang menunjukkan kandungan
lembapan yang tertinggi. Selain daripada itu, tekanan air liang tanah untuk kedua jenis tanah ini menunjukkan
pengurangan semasa hujan, tetapi beransur meningkat semasa proses pengeringan.
Selain daripada itu, didapati tekanan air liang antara
5 dan 10 cm tensiometer menunjukkan kesan pada pasir berkerikil berbanding
dengan tanah dari kampus.
Kata kunci: Kandungan
lembapan; penyusupan; tekanan liang; tiang tanah
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*Pengarang
untuk surat-menyurat; email: mmukhlis@vlsi.eng.ukm.edu.my
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