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Load Test on Combined Pile and Cap / Pad Foundation System on Compressible Calcareous Sand and Comparison with FEM Modelling Abram Kris Wicaksono; Petrus Chanel Suprihadi Santoso; Paulus Pramono Rahardjo
Indonesian Geotechnical Journal Vol. 2 No. 3 (2023): Vol. 2, No. 3, December 2023
Publisher : Himpunan Ahli Teknik Tanah Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56144/igj.v2i3.60

Abstract

An optimum type of foundation is expected to support 2 – 3 stories residential house on reclamation area to avoid deep foundation. The foundation will sit on engineering fill that constructed with calcareous sand which is classified as compressible sand. Below that part, at the original ground medium density sand and very soft marine clay is found stratified. Typical column in the residential building will have about 100 tons load intensity and based on this project, the design load for a single pile is 32 ton. Since no additional compression on soft clay layer is expected after building construction, than combine cap/pad foundation with short pile 6.5 m length is proposed. Load test with stress cell for this combine pile and cap/pad foundation was performed. The load test result show that interpretation using Chin’s and Mazurkiewicz’s Method obtained that the combined pile and cap/pad foundation’s ultimate bearing capacity of 112 – 119 tons. Analysis using stress cell data shows that the cap/pad carry about 31.8 % of the total load. Finite element analysis with axisymmetric condition conducted to study load distribution on combine pile and cap/pad foundation system. Analysis result was show that the cap or pad can carried about 38.1% of design load during testing. The 6.3% deviation between the stress cell and FEM results could be attribute by the assumption when calculating the load acting on cap/pad foundation. The stress cell analysis used the assumption that the load carried by the cap/pad foundation was uniform while the FEM results showed a non-uniform load.
The Use Of Lightweight Material At Road Access Construction On Slope Hansen Tananda; Aris Handoko; Paulus Pramono Rahardjo
Indonesian Geotechnical Journal Vol. 2 No. 3 (2023): Vol. 2, No. 3, December 2023
Publisher : Himpunan Ahli Teknik Tanah Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56144/igj.v2i3.61

Abstract

To achieve the design elevation from the existing ground level, an embankment work with a thickness of 8-10 meters thick on the slope should be conducted considering both the safety aspect as well as the economic aspect. Based on the conceptual drawing by Contractor, the embankment will sit on the slope without any grading works. The drawing shows that the embankment will be constructed directly on the existing slope. Any fill work on the original slope without any proper reinforcement will cause stability issues.  The discussion about the embankment area construction concept has come up with some options such as the use of a slab-on-pile system and the use of a combination sheet pile - bore piles and the use of mini piles under the embankment. Based on further discussion with Contractor and Owner about the technical aspect and construction cost required, it is recommended to construct an embankment with lightweight material (geofoam). The use of lightweight geofoam is a suitable solution to be considered. Another advantage of using geofoam is that the construction period is faster than conventional methods. Geofoam installation work already started on November 2022. On February 2023, the geofoam slope construction finished.
Evaluasi Shear Strength dan Stress History Tanah Lunak pada Pekerjaan Vacuum Preloading Menggunakan Uji CPTu Fenny Septiastuti; Paulus Pramono Rahardjo; Rinda Karlinasari Indrayana
Jurnal Teknik Sipil Vol 30 No 3 (2023): Jurnal Teknik Sipil
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/jts.2023.30.3.7

Abstract

Makalah berikut menyajikan evaluasi nilai shear strength dan stress history tanah lunak menggunakan CPTu. Lokasi penelitian berada di Kosambi Tangerang, pada tanah Jakarta marine clay. Pada area penelitian dilakukan pematangan lahan menggunakan prefabricated vertical drain (PVD) yang dikombinasikan dengan vacuum preloading sebesar 80 kPa. Dalam penelitian ini disebut metode konsolidasi vakum. Penelitian ini bertujuan untuk mengukur efektifitas pekerjaan konsolidasi metode vacuum preloading. Metode pengukuran efektivitas konsolidasi vakum menggunakan evaluasi nilai shear strength dan stress history dari CPTu. Hasil analisis dapat menunjukkan beban vacuum preloading yang diterima di setiap lapisan tanah. Besar derajat konsolidasi menggunakan analisis settlement plate tidak selalu mencerminkan besar peningkatan nilai kuat geser tanah. Nilai derajat konsolidasi tanah pada vacuum preloading lebih mendekati kondisi aktual jika menggunakan acuan peningkatan kuat geser tanah daripada hasil analisis settlement plate. Tanah Jakarta marine clay memiliki nilai α berkisar 2.5 dan nilai Ch mendekati nilai Cv. The following paper shows an evaluation of the shear strength and stress history values of soft soils using CPTu. The research location is in Kosambi, Tangerang, on Jakarta marine clay soil. In the research area, ground preparation was carried out using a prefabricated vertical drain (PVD) combined with a vacuum preloading of 80 kPa. In this study it is called vacuum consolidation method. This study aims to measure the effectiveness of consolidation using vacuum consolidation method by using the evaluation of shear strength values and stress history of CPTu. The results of the analysis can show the vacuum preloading load received in each soil layer. The result of consolidation degree using analysis of settlement plate does not always indicate the increase of shear strength in the soil. The value of degree consolidation on the vacuum preloading is closer to the actual condition when using the increasing shear strength compared to the result analysis from the settlement plate. Jakarta marine clay soil has an α value of around 2.5 and the Ch value is close to the Cv value.
Excess Pore Pressure Migration Analysis Due to High Embankment Construction – Case Study East Kalimantan Lie, Edwin; Rahardjo, Paulus Pramono; Wijaya, Martin
Journal of the Civil Engineering Forum Vol. 10 No. 2 (May 2024)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.9713

Abstract

A 42-inch pipeline traverses a predominantly flat right-of-way (ROW), running from south to north in East Kalimantan. Adjacent to the ROW, a coal mine concession was located on the western side, while the Mahakam River lies a further 3 km to the east. A mining waste dump has been constructed since 2010, situated in an area underlain by soft alluvium soil (Qa). The waste was stacked, reaching heights of up to 75 meters, with its toe approximately 200 m from the edge of the ROW. In 2016, a failure occurred in the ROW, causing the 42-inch pipeline to shift a maximum of 6.8 m horizontally, and rise by 2.0 m within a 300 m span. A geotechnical investigation was then conducted, consisting of 7 CPTu with dissipation testing. The CPTu results indicated high pore pressure, with a layer of soft clay ranging from 15 to 32 m thickness found in the ROW area. A hypothesis was formulated suggesting that the soft clay was not fully consolidated. Hence, the failure of the pipeline was possibly caused by the migration of excess pore water pressure accumulated during the construction of the waste dump. Results of the investigation indicated that the permeability coefficient was 2.5 times greater in the horizontal direction compared to the vertical ones (kh/kv = 2.5), allowing the pore water pressure to migrate more easily in the horizontal direction. This study aims to elucidate how the migration of excess pore water pressure in the horizontal direction influences ground stability. The analysis was conducted using finite element software MIDAS GTS NX, with the kh/kv varying from 2.5 to 100 times to explore excess pore pressure movement behaviors. The results of this study confirm that excess pore pressure migration can occur horizontally if the horizontal permeability coefficient is larger than its vertical counterpart. Thus, this study highlights that the greater the permeability coefficient and the larger the ratio, the further the excess pore pressure travels. Moreover, the horizontal displacement increases with the permeability coefficient ratio.
Karakterisasi Tanah Vulkanik di Kabupaten Kediri, Jawa Timur, Indonesia Berdasarkan Uji CPT, SPT, dan PMT: Site Characterization of Volcanic Soil in Kediri Regency, East Java, Indonesia Based On CPT, SPT, and PMT Wiwarsono, Fransisko; Rahardjo, Paulus Pramono; Sadisun, Imam Achmad
Cantilever: Jurnal Penelitian dan Kajian Bidang Teknik Sipil Vol. 12 No. 2 (2023): Cantilever
Publisher : Department of Civil Engineering and Planning, Faculty of Engineering, Sriwijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35139/cantilever.v12i2.205

Abstract

Indonesia is a country surrounded by the Pacific Ring of Fire so that various areas are dominated by volcanic soil. Volcanic soils have unique and unusual characteristics, different structures and properties from soil in general, and are strongly influenced by geological processes. Volcanic soils were also found to be problematic and caused a lot of geotechnical damage. Research on volcanic soils from a geotechnical perspective in Indonesia is still very limited. This study aims to characterize volcanic materials in Kediri Regency, East Java, Indonesia, based on in situ testing using CPT (Cone Penetration Test), Standard Penetration Test (SPT), and Pressuremeter Test (PMT). CPT and SPT are the most common and frequently used field tests, while PMT is used to obtain horizontal stresses. Some data from the X-Ray Diffraction Analysis (XRD) test and corebox drilling results will also be used in this study. Field test results will display soil classification and parameters, which will then be combined, and empirical correlations will be obtained for site characterization as well as comparisons with other volcanic soil literature studies. The results showed that the volcanic soil in Kediri Regency consists of non-lateritic to lateritic soil. Based on the CPT and SPT correlations, it was found that the qc/N value was greater than in general soils for both cohesive and non-cohesive soils. The authors also found a relationship between parameters and interpretation of PMT data against NSPT for cohesive volcanic soils in the study area.
Evaluasi Perilaku dan Viskositas Material Pasir Kelanauan pada Kondisi Terlikuifaksi dengan Menggunakan Piezocone Albert Johan; Paulus Pramono Rahardjo; Budijanto Widjaja
Jurnal Teknik Sipil Vol 31 No 3 (2024): Jurnal Teknik Sipil - Edisi Desember
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/jts.2024.31.3.7

Abstract

Abstract Liquefaction is phenomenon of the loss of shear strength of saturated sandy soil. Liquefaction has become one of the primary concerns for Indonesia and the world, especially after the occurrence of liquefaction in Palu due to Palu-Donggala earthquake. Learning from the liquefaction phenomena after the Palu-Donggala earthquake event on 28 September 2018, many researchers have conducted liquefaction and flow slide study. In order to complete the study of the liquefaction phenomenon, an experimental study using shake table, chamber, and piezocone is conducted to evaluate the behaviour and viscosity of liquefied silty sand material. Based on the observation during liquefied condition, the silty sand material will experience an increase in excess pore pressure and a decrease in tip resistance. In addition, it is also known that sleeve resistance, speed of penetration of the piezocone, and zone of influence due to piezocone penetration are the main keys in determining the viscosity of the silty sand material during liquefied condition Keywords: Liquefaction, viscosity, silty sand, piezocone
KAJIAN KARAKTERISTIK DAN KECEPATAN KONSOLIDASI PADA TANAH LAKUSTRIN BANDUNG Georgeshua, Cornelius; Rahardjo, Paulus Pramono; Desiani, Asriwiyanti
JMTS: Jurnal Mitra Teknik Sipil Volume 8, Nomor 1, Februari 2025
Publisher : Prodi Sarjana Teknik Sipil, FT, Universitas Tarumanagara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24912/jmts.v8i1.31953

Abstract

Bandung is an ancient lake area formed by years of sedimentation. The result of the sedimentation is then called the Bandung lacustrine soil where the soil has very soft characteristics, is water saturated, has relatively high voids, low shear strength and is very compressible. This study aims to determine the consolidation characteristics of Bandung Lacustrine soil in the Gedebage area using CPTu Test, Drill Test, SPT Test, Laboratory Test and settlement plate instrumentation. CPTu Test, Drill Test and SPT Test are intended to determine the layering and depth of the Bandung Lakustrine soil where the Bandung Lakustrine soil is at a depth of 5 - 30 m. Laboratory and Settlement Plate tests were conducted to determine the physical characteristics and consolidation of the Bandung Lakustrine soil. From this research, it is known that Bandung Lakustrin soil has high moisture content (Wn > 200%), high pore number value (e > 4), relatively high primary and secondary strain value (Cc = 2 - 4 & Ca = 0.005 - 0.09), and relatively high strain (12 - 54%), coefficient of consolidation (Cv) ranges from 2.49 - 16.18 x10-3 cm2/s based on CPTu dissipation data. ABSTRAK   Bandung merupakan daerah danau purba yang terbentuk akibat sedimentasi bertahun-tahun. Hasil sedimentasi tersebut yang kemudian disebut dengan tanah lakustrin bandung dimana tanah memiliki karakteristik yang sangat lunak, jenuh air, memiliki void yang relatif tinggi, kuat geser yang rendah dan sangat kompresible. Penelitian ini ditujukan untuk mengetahui karakteristik konsolidasi pada tanah Lakustrin Bandung pada kawasan Gedebage menggunakan Uji CPTu, Uji Bor, Uji SPT, Uji Laboratorium dan instrumentasi settlement plate. Uji CPTu, Uji Bor dan Uji SPT ditujukan untuk mengetahui pelapisan dan kedalaman dari tanah Lakustrin Bandung dimana tanah Lakustrin Bandung berada pada kedalaman 5 – 30 m. Uji Laboratorium dan Settlement Plate ditujukan untuk mengetahui karakteristik fisik dan konsolidasi tanah Lakustrin Bandung. Dari penelitian ini diketahui bahwa Tanah Lakustrin Bandung memiliki kadar air yang tinggi (Wn > 200%), nilai angka pori yang tinggi (e > 4),  nilai regangan primer dan sekunder yang relatif tinggi (Cc = 2 – 4 & Ca = 0.005 – 0.09), dan reganan yang relatif tinggai (12 – 54%), koefisien konsolidasi (Cv) berkisar 2.49 – 16.18 x10-3 cm2/dt berdasarkan data disipasi CPTu.