Perkembangan teknologi dan peramalan terkini dalam melakukan kajian terhadap
fenomena semulajadi terhadap keruk di sekitar pier semakin meluas. Ini adalah kerana
faktor peramalan sangat penting bagi mewujudkan satu kombinasi rekabentuk yang
selamat, ekonomi serta seimbang. Keruk terbentuk hasil daripada aliran bergelora yang
dihalang oleh pier sesuatu jambatan dan menyebabkan proses degredasi pada pier di dasar
sesuatu sungai berlaku dalam suatu jangkamasa yang panjang. Fenomena keruk yang wujud
di sekitar pier pada sesuatu jambatan akan mengganggu kekuatan struktur yang
direkabentuk jurutera lalu menyebabkannya gagal. Tetapi, kaedah peramalan ini tidak dapat
digunakan untuk mendapatkan suatu nilai yang tepat disebabkan faktor persekitaran yang
sentiasa berubah. Oleh sebab itu, ia tidak sesuai untuk diaplikasikan untuk semua keadaan.
Di samping itu, melalui peramalan yang dibuat, risiko untuk sesuatu jambatan mengalami
kegagalan adalah sangat rendah sekiranya faktor peramalan ini diambilkira semasa
rekabentuk dibuat. Kajian telah dilakukan oleh Simon dan Senturk (1992), Kafi dan Annan
(1995) dimana mereka telah berjaya membangunkan beberapa persamaan bagi tujuan
peramalan. Mereka berpendapat sekiranya pekali bagi pemalar dan eksponen bagi
persamaan ini diterbitkan dengan menggunakan data lapangan, ketepatannya adalah
semakin tinggi. Berdasarkan cadangan tersebut, Ab. Ghani dan Nalluri (1996) telah
membangunkan beberapa persamaan baru bagi mengatasi setiap kelemahan yang wujud
untuk mendapatkan nilai kejituan yang lebih tinggi berpandukan data lapangan tersebut.
Melalui kajian ini, analisis akan dilakukan dengan menggunakan perisian S-PLUS melalui
tiga kaedah regresi teguh.
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Over the decades, excessive local scour around bridge piers have been the major
contribution factors for bridges deficiencies and failures. Technological breakthroughs in
modern engineering have provided efficient tools for construction experts and engineers in
making statistical analysis, to find the best method to deal with this phenomenon. The
analysis is crucial since it would provide the quantitative evaluations to designers, which
would help them to model a structure that combined safety, balances and economics. There
are many reasons why scour became a major concern in designing bridges. Bridges that
become inundated during floods have slightly pressurized flow that impacts bridge piers
and creates an aggravated scour condition. Bridge failure mode which induced by scour is
relatively complex since it involved a combination of factors such as the combined ejects of
three dimensional river bed degradation, localize scour due to channel constriction at the
bridge opening, and the accelerated flow and generation of vortices at the bridge opening
which caused local scour around bridge piers and abutments. Due to the seriousness of the
scour problem, bridge design will take into consideration all factors available. Equations
were developed by subject matter experts, to make forecasting to eliminate or minimize its
impact on the structure. Unfortunately, the ever changing environmental phenomena have
made those equations not suitable to be applied to all conditions. Studies by Simon &
Senturk (1992) and Kafi & Alam (1995) have proposed various scour equation which have
been developed in the literature. It is found that the precision and accuracy of laboratorybased
equations can improved if the coefficient and exponent of these equations were
derived using field data. Apart from that, the equations are dependent to several factors;
flow criteria such as flow depth, flow velocity and vortex velocity, shape of the pier and
size of sediment. Based on the suggestion by Kafi & Alam (1995), Ab.Ghani & Nalluri
(1996), new equations were developed to predict pier scour using the available field data. In
this study, analysis has been made by using S-PLUS with 3 method of analysis.
Peramalan kedalaman keruk di sekitar pier menggunakan kaedah regresi teguh / Ahmad Hakimi Mohamed