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Investigation of Pile Behavior Toward Abutment Construction using PLAXIS 3D: Case Study on Lembak Bridge Clinton Girsang; Paulus Pramono Rahardjo; Aswin Lim
U Karst Vol. 5 No. 1 (2021): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i1.1012

Abstract

Soil  as  a  subgrade  foundation  under  embankment  construction often  creates  problems  in  terms  of  stability  and  settlement. Therefore, it needs improvement by using preloading embankment. This article presents the investigation of pile behavior towards two scenarios  of  abutment  construction  using  Plaxis  3D,  a  three- dimensional  finite  element  program.  The  use  of  two  scenarios  of analysis was Method A. The abutment construction phase conduct without using a preloading embankment, and Method B, where a preloading  embankment  constructs  before  the  abutment construction.  The  case  study  location  at  the  Lembak  bridge. Compare  the  analysis  results  with  the  measured  data.  Results showed that Method A and Method B's pile deflection yielded four times  and  one  point  six  times  larger  than  the  measure  data, respectively.  Hence,  it  indicates  that  Method  B  recommends  for future construction of bridge abutment.
Investigation of Twin Tunnel Deformation with Umbrella Grouting Protection & NATM Tunneling using 3D Finite Element: Case Study Cisumdawu Tunnel Wellyanto Wijaya; Paulus Pramono Rahardjo; Aswin Lim
U Karst Vol. 5 No. 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i2.1977

Abstract

Cisumdawu Tunnel is a twin tunnel 472 m long located in Sumedang. Twin tunnel construction can cause additional ground settlement and tunnel deformation. The tunnel construction method used is the New Austrian Tunneling Method (NATM) and umbrella grouting protection system. The principle of NATM is to maximize surrounding soil capacity to support its weight and balance the stresses around the tunnel. Investigation of tunnel deformation is important to know tunnel structure behavior and avoid possible failure. This research aims to know tunnel deformation and the effect of twin tunnel construction on the deformation and ground settlement. The data used such as tunnel geometry, monitoring data, pressuremeter test, and the drilling test. The 3D analysis will be performed for a single tunnel and twin tunnel using Midas GTS-NX, and monitoring data will be used for verification analysis. The 3D FEM help to model the soil condition and construction stage according to the actual condition. The analysis results show the maximum tunnel deformation that occurs from the beginning of the tunnel construction is 12.64cm. If the deformation starts to be calculated following the monitoring reading time, after the excavation at the monitoring point, the maximum deformation of the analysis results is 3.3&4.4cm, where the monitoring shows maximum deformation of 3.3&4.3cm. Through the results, it can be said that the analysis using 3D FEM with pressuremeter test parameter represents actual conditions. Twin tunnel construction side-by-side increases ground settlement and lateral tunnel deformation significantly. Hence, it shows that tunnel analysis using 3D FEM recommends for future investigation of tunnel deformation.
Perbaikan Tanah Lunak Menggunakan Campuran Ferronickle Slag Dan Kalium Serta Natrium Hidroksida Aswin Lim; Evan Darian
Jurnal Rekayasa Sipil Vol 18, No 3 (2022)
Publisher : Civil Engineering Departement, Andalas University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrs.18.3.202-213.2022

Abstract

Tanah lunak merupakan salah satu tanah yang bermasalah pada dunia konstruksi karena memiliki kuat geser tanah yang rendah serta kompresibilitas yang tinggi. Perbaikan tanah merupakan salah satu solusi untuk menghadapi masalah ini. Pada penelitian ini, tanah Kaolin digunakan untuk memodelkan karakteristik tanah lunak. Material ferronickel slag yang merupakan limbah produksi nikel digunakan sebagai binding agent, pengganti semen yang sudah sering digunakan untuk perbaikan tanah. Selain itu, larutan alkali (kalium hidroksida dan natrium hidroksida) yang memiliki konsentrasi tinggi digunakan sebagai aktivator untuk mengaktivasi kaolin sehingga terjadi proses pembentukan geopolimer. Pada penelitian ini, massa slag yang digunakan adalah 10% dari massa kaolin, sedangkan larutan alkali yang digunakan adalah dengan variasi 6 M, 8M, dan 10M. Setelah kaolin dicampur dengan komposisi yang ditentukan, dilakukan masa curing selama 7, 14, dan 28 hari sebelum sampel dilakukan uji kuat tekan bebas. Dari hasil pengujian, dapat disimpulkan bahwa larutan natrium hidroksida lebih efektif digunakan sebagai aktivator, serta kuat tekan bebas sampel paling tinggi berada pada masa sampel berumur 28 hari setinggi 933 kPa dengan konsentrasi 8M. Sedangkan, nilai kuat tekan bebas dengan larutan kalium hidroksida adalah 896 kPa dengan konsentrasi 10M. Selanjutnya, uji Scanning Electron Microscope  dan X-Ray Fluoresence Spectrometer juga dilakukan pada menginvestigasi ikatan kimia yang terjadi pada sampel. Dari uji SEM dan XRF, terbukti juga sampel campuran membentuk gugus/ikatan geopolymer, dan reaksi kimia terjadi. Penambahan Kalium Hidroksida akan menambah senyawa K2O, dan penambahan natrium hidroksida akan menambah senyawa Na2O. Hal ini dapat menjelaskan alasan meningkatnya kuat tekan bebas tanah campuran.
Soil Improvement of Petobo Silty Sand using Ferronickel Slag and Alkaline Activators Aswin Lim; Adrianus Renaldy; David Kristian
Applied Research on Civil Engineering and Environment (ARCEE) Vol. 4 No. 02 (2023)
Publisher : POLITEKNIK NEGERI JAKARTA

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

This study aims to provide an alternative soil improvement that can be applied in the Petobo area, which experienced liquefaction on September 29, 2018. Ferronickel slag is utilized as a binding agent. Furthermore, large concentrations of alkaline solutions (potassium hydroxide and sodium hydroxide) are utilized as activators to activate kaolin and initiate the geopolymer production process. From the test results, it can be concluded that sodium hydroxide and potassium hydroxide solutions are effective to be applied as an alkaline solution. The maximum unconfined compressive strength of the sample is about 530 kPa with a concentration of 10% of ferronickel slag and 10M of alkaline activator. This value is twice larger than if we applied cement to the soil with the same amount of concentration. Hence, the effect of the admixture of ferronickel slag and alkaline activator is more dominant than the admixture of cement only. Furthermore, the Scanning Electron Microscope and X-Ray Fluorescence Spectrometer tests were also carried out to investigate the chemical bonds that occurred in the samples. It is revealed that the geopolymer matrix envelops soil particles resulting from the geopolymer reaction. The composition of SiO2 and Al2O3 in the treated Petobo silty sand decreased. It might be due to the geopolymer reaction that occurs in the sample so that the content of SiO2 and Al2O3 compounds is reduced. Because it uses an activator in the form of a KOH and NaOH solution, there is an increase in the levels of MgO compounds in the sample compared to untreated Petobo silty sand.
STUDI LABORATORIUM CAMPURAN BIOPOLIMER GLUKOMANAN DAN BEESWAX UNTUK MENINGKATKAN KUAT GESER TANAH PASIR Andra Ardiana; Aswin Lim; Henky Muljana; Heriansyah Putra; Budijanto Widjaja
Jurnal Teknik Sipil Vol. 17 No. 3 (2023)
Publisher : Program Studi Teknik Sipil Fakultas Teknik Universitas Atma Jaya Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24002/jts.v17i3.6968

Abstract

Pada saat ini, pemakaian semen Portland (OPC) pada dunia konstruksi mulai dikurangi dan dialihkan ke material yang ramah lingkungan, seperti biopolimer. Biopolimer adalah polimer alami yang berasal dari tumbuhan, hewan, alga, jamur, atau sumber bakteri yang terdiri dari polisakarida. Penggunaan biopolimer sebagai bahan organik memiliki tantangan tersendiri yaitu sifatnya yang sangat sensitif terhadap air dan mengalami biodegradasi. Pada penelitian ini, sifat sensitif terhadap air akan coba dikurangi dengan mencampur sampel pasir silika dengan lilin lebah (beeswax) yang bersifat hidrofobik dan biopolimer yang digunakan adalah glukomanan. Selain itu, metode pencampuran sampel pada kondisi basah dan kondisi kering juga ditinjau untuk memperoleh metode yang lebih baik untuk pencampuran sampel. Hasil uji laboratorium menunjukan peningkatan nilai kohesi sebesar 264,8 kPa dan sudut geser dalam sebesar 44,7 ̊ serta nilai Undrained shear strength sebesar 525,8 kPa dari uji kuat tekan bebas dengan komposisi biopolimer 2 % glukomanan ditambah 2 % lilin lebah. Komposisi biopolimer yang seimbang antara glukomanan dan lilin lebah, suhu pemanasan 110 ̊ C, dan metode pencampuran basah merupakan kondisi yang paling optimal dalam pembuatan sampel uji.
Shear Strength Characteristics of Calcium Oxide and Guar Gum Treated Loose Petobo Silty Sand Yohanes Albrecht Montol; Aswin Lim; Paulus Pramono Rahardjo
Journal of Applied Engineering and Technological Science (JAETS) Vol. 5 No. 2 (2024): Journal of Applied Engineering and Technological Science (JAETS)
Publisher : Yayasan Riset dan Pengembangan Intelektual (YRPI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37385/jaets.v5i2.2583

Abstract

This article presents the shear strength characteristics of Petobo Silty Sand which are treated with Calcium Oxide and Guar Gum. The purpose of this experimental works is looking for other binding agents to replace the application of cement which is considered not an environmentally friendly material. The shear strength of treated soils was examined using the direct shear test. Guar gum and Calcium Oxide provides additional cohesion to Petobo silty sand. The cohesion and internal friction angle could increase to about 900 kPa and 47.5°, respectively. The treated sample also shows the dilation behavior in dry conditions. However, after 24 hours soaking period, the soil behavior returned to the contraction behavior. This behavior is unfavorable in the case of the treated sample below the groundwater table. Hence, these two binding agents are effective for dry soil conditions. In addition, Scanning Electron Microscope images of treated silty sand were obtained which aims to examine the microscopic behavior of the fibers and matrices that were formed through the hydration process.
Studi Kasus Pemodelan Vacuum Consolidation dan Prefabricated Vertical Drain Cheryl, Monica Frances; Lim, Aswin
Jurnal Komposit: Jurnal Ilmu-ilmu Teknik Sipil Vol. 8 No. 2 (2024)
Publisher : Universitas Ibn Khaldun

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32832/komposit.v8i2.16500

Abstract

Soft soil is soil with the potential for large consolidation settlements over a long period of time. Soft soil often causes problems for the structures above it due to the relatively low bearing capacity of the subgrade and long-lasting large soil compression. To accelerate the consolidation reduction that occurs, one of the latest steps for soil improvement is the vacuum consolidation method with a combination of prefabricated vertical drain (PVD). This method involves installing a vertical drain into soft soil where a vacuum pump will suck water and air in the soil which has been wrapped in airtight material on top. The vacuum process and application of vertical drain will cause a decrease in consolidation in the soil to occur more quickly. Initial loading with vertical drainage is carried out to induce most of the settlement of the underlying soil layer. The aim of this research is to model the soil improvement process with vacuum and PVD using the 2-dimensional finite element method. The study was carried out by carrying out reverse analysis, based on soil parameter data in North Jakarta which was adjusted to the decline curve over time in the field. Based on the analysis, the results obtained show that with the presence of PVD, the soil permeability in the horizontal direction of the model will increase so that the dissipation of pore water pressure will be faster. Plaxis modeling curves for reduction over time and pore water pressure over time have similar results to measurements in the field.
Evaluation of Degree of Consolidation, Over Consolidation Ratio and Coefficient of Consolidation from CPTu tests in Alluvium Clays Lie, Edwin; Lim, Aswin
INERSIA lnformasi dan Ekspose Hasil Riset Teknik Sipil dan Arsitektur Vol. 19 No. 2 (2023): December
Publisher : Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/inersia.v19i2.58976

Abstract

Soft soil was found in several areas in Indonesia, one of them is in Kalimantan Island, which the soft soil in the island mostly formed by Alluvium.  One of the characteristics of the soft soil is that they are likely still in under consolidating stage. The usage of CPTu was found to be suitable to the soft soil as the device can record small numbers continuously and able to record pore water pressure. Key features in performing CPTu in under consolidating soft soil is the dissipation test. However, often the dissipation test ended before the 50% excess pore pressure dissipated, which causes commonly used method for interpretation unable to estimate u50. Inverse time (Whittle et. al., 2000; Lim et. al., 2014) and inverse square root time (Liu et. al., 2014) method was developed to overcame the limitation. Rahardjo et. al. (2016) also developed method for obtaining degree of consolidation (and OCR) using pore pressure ratio parameter (Bq) obtained from CPTu.  Geotechnical investigation comprised advancing several cone penetration testings (CPTu) were carried out after failure occurred in a relatively flat area (RL +5m to +12m) after having built waste dump embankment to +70m elevation. Soft soil with 15m to 30m thickness was found beneath the embankment. This paper presents comparison of coefficient of consolidation using Teh & Houlsby (1991) method using parameters derived from inverse time and inverse square root time, also comparison for degree of consolidation and OCR in the Alluvium clays based on the dissipation data obtained from the testings.  Result showed that the Alluvium clays in the upper 10m already over consolidated while between RL 0 to -20m are still under consolidating, with parameters obtained using inverse time and inverse square root time generally showing close value.
Experimental Study of Cationic-Modified Biopolymer for Increasing the Shear Strength of Sand Ardiana, Andra; Lim, Aswin; Muljana, Henky
Jurnal Teknik Sipil dan Perencanaan Vol 26, No 1 (2024)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jtsp.v26i1.49722

Abstract

The application of biopolymers as a more environmentally friendly alternative to cement has emerged as an interesting research subject.The purpose is to enhance the shear strength of sandy soils. In this article, the selected biopolymer is cationic-modified starch. It is expected that cationic starch will have less water absorption properties since modified starch has cationic groups in place of the OH- groups found in the normal starch. This cationic-modified starch namely Amylofax. Five types of samples are created for this testing, including Sample A is prepared with the composition of  (silica sand + 2% Amylofax T1100 (w/w) + 20% water (w/w))., Sample B consists of (silica sand + 2% Amylofax T2200 (w/w) + 20% water (w/w))., Sample C is comprised of (silica sand + 2% Amylofax T1100 (w/w) + 2% Glucomannan (w/w) + 20% water (w/w)), Sample D consists of (silica sand + 2% Amylofax T2200 (w/w) + 2% Glucomannan (w/w) + 20% water (w/w)), and Sample E includes (Ottawa sand + 2% cement (w/w) + 20% water (w/w)). The samples were tested using a direct shear test apparatus to determine the soil shear strength parameters (c) cohesion and (Ø) internal friction angle. After conducting the tests on the sand samples with the addition of modified starch biopolymer (cationic starch), it was found that the cohesion value was 961kPa, and the internal friction angle was 63°. These results indicate higher shear strength values compared to sand mixed with natural starch.
Effects of EPS Beads on the Unconfined Compressive Strength and Stiffness of Bentonite Soil-Cement Mixture Lim, Aswin; Pratama, Ignatius Tommy; Verguson, Yoghi Jo
Jurnal Teknik Sipil dan Perencanaan Vol 25, No 1 (2023)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jtsp.v25i1.38056

Abstract

Expanded Polystyrene Beads (EPS Beads) have characteristics that are lightweight and low density. However, EPS is waste that does not pollute the soil, but has hundreds of years to decompose, thereby reducing the landfill area. Therefore, alternative disposal is to use EPS for soil improvement. The effects of different EPS beads size on the mechanical behavior of bentonite soil-cement mixture were studied using the unconfined compression test. The curing time of the mixture also varied from 7 to 28 days. The results indicate that adding EPS beads to the soil-EPS beads-cement mixture changed the behavior of the material to be more ductile. The samples could also support larger stresses at a lower strain level, less than 1 %. Furthermore, the unconfined compressive strength of the mixture of bentonite, EPS, and cement increased with increasing curing time and decreased with increasing EPS beads size. Then, adding EPS beads to the soil-cement mixture regardless of its size also promoted a larger stiffness of the samples compared to the sample with no EPS beads in the mixture.