Laboratory Pullout Tests On The Wire Mat Reinforcements With Weathered Clay As Backfill Material

The study of pullout mechanism was carried out on full scale pullout apparatus. The aim of this study is to identify the mechanism of pullout resistance of a reinforced weathered clay using welded wire and \u27A" diameter steel mesh. The results of the study showed the pullout force-displacement curves generally have a yield point at a displacement ranging from 4 - 6 mm, the pullout resistance increase with the diameter of wire. By comparing the test results using backfill material at different water content, it was found that weathered clay backfill material is more effective compacted at dry side than those of wet side and optimum moisture content

Perancangan Pelat Fondasi Sistem Cakar Ayam Dengan Metoda Balok PAda Fondasi Elastis

Cakar Ayam System has been used to support many structures including tower, buildings, runway etc. Design of this foundation needs to consider stability against bearing capacity failure, settlement as well as failure due to the breaking of foundation slab. The deflection, bending moment and shearing force on the foundation slab due to loading should be analysed properly. This paper present the method to analyse the structural stability of Cakar Ayam System using the method of Beam on Elastic Foundation. Keyword: Cakar Ayam system, modulus of vertical subgrade reaction, modulus of horizontal subgrade reaction, deflection, rotation, bending moment, shearing force

METODE VACUUM PRELOADING SEBAGAI SALAH SATU ALTERNATIF SOLUSI PEMBANGUNAN TIMBUNAN DI ATAS TANAH LUNAK

Banyak bangunan infrastruktur transportasi dibangun pada tanah lunak yang tebal, sehingga masalah penurunan yang berlebihan menjadi penting dan harus dicari solusinya. Pada lokasi tersebut, sebelum dilakukan pembangunan infrastruktur, umumnya dilakukan lebih dulu perbaikan tanah guna menjamin stabilitas jangka pendek maupun jangka panjangnya. Cara-cara perbaikan tanah yang yang lazim dilakukan dapat berupa pembongkaran dan penggantian, prapembebanan, drainase vertikal, injeksi, stabilisasi tanah, perkuatan tanah dan lain-lainnya. Salah satu alternatif cara perbaikan tanah yang sering digunakan dalam Pembangunan timbunan pada tanah lunak adalah drainase vertikal. Dalamperkembangannya, pada waktu sekarang ini, drainase vertikal konvensional dikombinasikan dengan prapembebanan vakum. Beberapa keuntungan dapat diperoleh dari cara ini, antara lain tinggi timbunansebagai preload dapat direduksi dan masalah ketidakstabilan lereng timbunan saat pembangunan dapat diminimalkan. Keberhasilan pemakaian metode vakum ini bergantung banyak faktor, seperti: kebocoransistem membran, adanya lensa-lensa tanah lolos air di dalam zona tanah yang ditangani. Makalah ini menyajikan state-of-the art dari berbagai hal yang menyangkut teori dan aplikasi metode prapembanan vakum bila digunakan dalam perbaikan tanah lunak

PENGARUH SPASI ANTAR LEMBAR PERKUATAN TERHADAP KARAKTERISTIK KEKUATAN PASIR YANG DIPERKUAT = Effects of Reinforcement Fabric Spacing Due to The Strength Characteristics of Reinforced Sand

ABSTRACT The objectives of this research was to study the behavior of Sundak beach sand that reinforced by nonwoven geotextile, and to explore additional knowledge and references on reinforced soil in Indonesia. Many researchers had proved that triaxial compression equipment could be used to study the behavior of reinforced soil by reinforcement fabrics. Conventional triaxial compression tests had been conducted using standard specimen with 70 mm dia. and 147 mm height. Nonwoven polyfelt geotextile was used as reinforcement. Test results were plotted as stress-strain curves and analyzed by Mohr circle and Mohr-Coulomb failure envelope. The results showed that the spacing between reinforcement fabrics affected significantly on the sample strength. Furthermore, uniformity of spacing between reinforcement fabrics was also the important factor that influenced the strength of reinforced sand. Keywords: spacing between reinforcement fabrics, strength, reinforced san

The Study of The Usage of Vacuum Preloading Method in The Construction Project Of Palembang – Indralaya Toll Road

Palembang – Indralaya (Palindra) Toll Road is part of the Trans Sumatera Toll Road built on soft soil. Soil improvement using vacuum preloading method has been conducted to resolve the problem. The method involves replacing a surcharge load with an atmospheric pressure and utilizing vertical and horizontal drains, as well as sand blanket. Factors that influence the effectivity of the performance of the vacuum method comprise the settlement, the time of settlement, the speed of settlement, the degree of consolidation, the distance of the Prefabricated Vertical Drain or PVD, and so forth. The result of the settlement using Terzaghi’s equation combined with Indraratna’s showed that the addition of the height of the fill would have been effective if it had been equal or larger than the vacuum pressure that was used (80 kPa). It could be observed from attaining faster consolidation time of 56 days. The analysis result was, then compared with the final settlement by using Asaoka method. The design of the PVD distance by using vacuum method showed that the spacing (S) was less restrained, which was 1,23 m, compared to the one using with extra load (surcharge) which was 1,2 m. The settlement of vacuum consolidation was 1,98 m, which was smaller than the surcharge one that reached 2,11 m

Perilaku Lintasan Tegangan (Stress Path) Pada Tanah Gambut Rawaseragi Lampung

Peat is soil with a high organic content, water content, and compressibility, and also low bearing capacity. Peat have difference behavior and characteristic among one site with the other site. Stress path method can be used to represent the behavior of peat soil during the loading. This paper present the behavior of stress path on Rawaseragi Lampung peat soil using triaxial apparatus 36 mm dia, and 76 min height of specimen. The consolidated drained and consolidated undrained triaxial tests were conducted on sample of Lampung peat, with the variation of cell pressure 50 kPa, 100 kPa, 200 kPa and, 400 kPa. The results of triaxial test analysis with stress path method to find soil parameters show that Lampung peat are described as fibrous peat. The maximum deviator stress reached at strain 10% -16% and 9% - 16% for consolidated drained and consolidated undrained, respectively. Based on the critical \u27state line Lampung peat is near to normally consolidated, with the intersection value of critical state line to q axis is equal to 19,459 kPa and pore pressure change is always positive (Au > 0). Soil parameters were found to be : M = 0,86682. = 0,1058N = 4,0615and T = 4,0114. Key words : peat, stress path, triaxial test, critical state lin

PERANCANGAN ULANG KONSTRUKSI JALAN MENGGUNAKAN SISTEM PELAT TERPAKU SEBAGAI PERKERASAN PADA JALAN POROS SAMARINDA-BONTANG

Abstract   Section SP.3 Lempake–SP.3 Sambera is the section with the highest traffic volume on Jalan Poros Samarinda–Bontang, resulting in a lot of pavement damage. The damage to the road segment was caused by several factors, namely heavy vehicles, poor soil characteristics, non-functioning drainage, and the road section is located in the lowlands. The purpose of this research is to design a nailed slab system as a pavement to be used as an alternative to road pavement. The design was carried out using the AASHTO method and the Beam on Elastic Foundation method, with the load P at the center and at 0.30 m from the edge of the plate. The equivalent modulus reaction obtained for the AASHTO method was 48,515.785 kN/m³ and the resulting pavement slab thickness was 32.26 cm. While the Beam on Elastic Foundation method uses an equivalent modulus reaction value of 127,715.785 kN/m³ and the resulting pavement slab thickness is 20 cm. However, nailed slab system pavements are more expensive, because the total cost to be incurred is IDR 549,846,268,988, which is much higher than the total cost for conventional pavements, which is IDR 292,549,365,858.   Keywords: road pavement; rigid pavement; nailed slab system; conventional pavement.     Abstrak   Ruas SP.3 Lempake–SP.3 Sambera merupakan ruas dengan volume lalu lintas tertinggi di Jalan Poros Samarinda–Bontang, sehingga mengalami banyak kerusakan. Kerusakan pada ruas jalan tersebut disebabkan oleh beberapa faktor, yaitu kendaraan berat, karakteristik tanah yang kurang baik, drainase tidak berfungsi, dan ruas jalan terletak di dataran rendah. Tujuan penelitian ini adalah merancang sistem pelat terpaku sebagai perkerasan untuk dijadikan alternatif perkerasan jalan. Perancangan dilakukan dengan metode AASHTO dan metode Beam on Elastic Foundation, dengan beban P di pusat dan di 0,30 m dari tepi pelat. Nilai modulus reaksi ekivalen yang diperoleh untuk metode AASHTO adalah 48.515,785 kN/m³ dan tebal pelat perkerasan yang dihasilkan adalah 32,26 cm. Sedangkan metode Beam on Elastic Foundation menggunakan nilai modulus eaksi ekivalen 127.715,785 kN/m³ dan tebal pelat perkerasan yang dihasilkan adalah 20 cm. Akan tetapi, perkerasan sistem pelat terpaku lebih mahal, karena total biaya yang harus dikeluarkan adalah Rp549.846.268.988, yang mana nilai ini jauh lebih besar daripada total biaya untuk  perkerasan konvensional, yaitu Rp292.549.365.858.     Kata-kata kunci: perkerasan jalan; perkerasan kaku; sistem pelat terpaku; perkerasan konvensional

Mineralogical and Geochemical Control of Altered Andesitic Tuff upon Debris Slide Occurences at Pelangan Area, Southern Mountain of Lombok Island, Indonesia

Debris slides were recently found in the Pelangan area at Southern Mountain of Lombok Island, Indonesia. Pelangan is well known as the gold mineralization and hydrothermal alteration area. This study is aimed to identify the mineralogy and geochemistry of altered andesitic tuff that controlled slope instability and induced debris slides. For this purpose, it is necessary to prepare the field observation and laboratory analyses. Landslide inventory reveals that the Pelangan debris slides mostly occur in altered andesitic tuff. Based on the outcrop observations in the field, andesitic tuff found around the Pelangan debris slides have been altered in general. The strong intensity of alteration developed by hydrothermal alteration in this study area produces large amount of clay minerals especially montmorillonite, kaolinite, and illite. The abundance of those clay minerals reflect the intermediate argillic alteration. Montmorillonite is a type of clay mineral that easily swells at wet condition and easily shrinkages at dry condition. Swelling of clay mineral destroys intersheet and interlayer bonds, and reduces shear strength. The presence of clay minerals in the altered andesitic tuff of intermediate argillic zone can be considered as one of the factors that induced to the Pelangan debris slides. Further studies on geotechnical and slope stability analysis of the landslide area are crucial to be done for better understanding of the characteristics of the altered rocks inducing hazardous landslides

PERANCANGAN ULANG KONSTRUKSI JALAN MENGGUNAKAN SISTEM PELAT TERPAKU SEBAGAI PERKERASAN PADA JALAN POROS SAMARINDA-BONTANG

Abstract   Section SP.3 Lempake–SP.3 Sambera is the section with the highest traffic volume on Jalan Poros Samarinda–Bontang, resulting in a lot of pavement damage. The damage to the road segment was caused by several factors, namely heavy vehicles, poor soil characteristics, non-functioning drainage, and the road section is located in the lowlands. The purpose of this research is to design a nailed slab system as a pavement to be used as an alternative to road pavement. The design was carried out using the AASHTO method and the Beam on Elastic Foundation method, with the load P at the center and at 0.30 m from the edge of the plate. The equivalent modulus reaction obtained for the AASHTO method was 48,515.785 kN/m³ and the resulting pavement slab thickness was 32.26 cm. While the Beam on Elastic Foundation method uses an equivalent modulus reaction value of 127,715.785 kN/m³ and the resulting pavement slab thickness is 20 cm. However, nailed slab system pavements are more expensive, because the total cost to be incurred is IDR 549,846,268,988, which is much higher than the total cost for conventional pavements, which is IDR 292,549,365,858.   Keywords: road pavement; rigid pavement; nailed slab system; conventional pavement.     Abstrak   Ruas SP.3 Lempake–SP.3 Sambera merupakan ruas dengan volume lalu lintas tertinggi di Jalan Poros Samarinda–Bontang, sehingga mengalami banyak kerusakan. Kerusakan pada ruas jalan tersebut disebabkan oleh beberapa faktor, yaitu kendaraan berat, karakteristik tanah yang kurang baik, drainase tidak berfungsi, dan ruas jalan terletak di dataran rendah. Tujuan penelitian ini adalah merancang sistem pelat terpaku sebagai perkerasan untuk dijadikan alternatif perkerasan jalan. Perancangan dilakukan dengan metode AASHTO dan metode Beam on Elastic Foundation, dengan beban P di pusat dan di 0,30 m dari tepi pelat. Nilai modulus reaksi ekivalen yang diperoleh untuk metode AASHTO adalah 48.515,785 kN/m³ dan tebal pelat perkerasan yang dihasilkan adalah 32,26 cm. Sedangkan metode Beam on Elastic Foundation menggunakan nilai modulus eaksi ekivalen 127.715,785 kN/m³ dan tebal pelat perkerasan yang dihasilkan adalah 20 cm. Akan tetapi, perkerasan sistem pelat terpaku lebih mahal, karena total biaya yang harus dikeluarkan adalah Rp549.846.268.988, yang mana nilai ini jauh lebih besar daripada total biaya untuk  perkerasan konvensional, yaitu Rp292.549.365.858.     Kata-kata kunci: perkerasan jalan; perkerasan kaku; sistem pelat terpaku; perkerasan konvensional