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Karakteristik Pemanpatan Tanah Gambut Dengan Variasi Serat Wulandari, Deny; Fatnanta, Ferry; Nugroho, Soewignjo Agus
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 5 (2018): Edisi 1 Januari s/d Juni 2018
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains

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Abstract

A peat soil has different characteristics compared to clay, therefore some consolidation tests are needed to obtain a proper compression method when construction are located on peat soils. The purpose of this research was to determine the compression characteristics of peat soil with fiber variation based on Gibson and Lo (1961) method and laboratory testing. This research used amorphous peat, a samples which taken from Tambang, Kampar. The first sample is undisturbed, and the second with zero fiber, 30 % fiber and 60 % fiber. The equipment used consist of modified consolidometer, with a diameter and height are 15 cm. The load were applied 10 kPa, 20 kPa, 40 kPa, 80 kPa and 160 kPa. Some loads were added every 14 days. The result showed that water content has no influence to settlement, and samples with great amount of water content has low strain. Samples with high fiber content and low unit weight, i.e. 60% of fiber content produce the highest strain. Therefore, unit weight is a very crucial point in determining settlement in this research. Square root of time method can’t be used on peat due to the different from settlement vs time root curve. The void ratio vs strain curve formed in concave shape due to the macropores and micropores inside the peat. On real condition and 30% of fiber samples, the time to reach 90 % of compressibility were reduced along with enhanced loads, the fiberless and 60 % of fiber samples were increased along with enhanced loads. Gibson and Lo method can’t be used on amorphous peat. Hence, it needs to be corrected with primary compression parameters (a), secondary compression parameters (b) and .Keywords: Peat, Amorphous, Fiber Content, Consolidometer
PENGARUH VARIASI JARAK PELAT HELICAL TERHADAP KAPASITAS DAYA DUKUNG TEKAN PONDASI HELICAL PILE PADA TANAH GAMBUT DENGAN METODE CONSTANT STRESS OF PENETRATION Fadhilah, Randy; Fatnanta, Ferry; Nugroho, Soewignjo Agus
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 5 (2018): Edisi 1 Januari s/d Juni 2018
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains

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Abstract

A study of the determination of helical pile bearing capacity based on static load test on peat soil has been done previously. However, the research is still covered in one method of loading which is the Constant Rate of Penetration (CRP). Therefore, it is deemed necessary to apply static load test on the helical pile on peat soils by using other loading method as a comparison. One of the test methods is Constant Stress of Penetration loading test. In this research, the helical piles used amounted to 9 piles. The loading were performed in six stages with a total load of 1200 kg. The data obtained from this test consist of settlement curve against time and loading curve against settlement. Determination of bearing capacities of helical piles were based on individual bearing and cylindrical shear method, and interpretation of test data based on Tangent Intersection and Terzaghi & Peck method. The results of the interpretation of the test data indicate that in the LMS (Large-Medium-Small)and LM (Large-Medium)helical pile groups have effective space between helical plates is from 20 to 30 cm. While in the LL (Large-Large) helical pile group, the effective space between the helical plates is from 30 to 50 cm. Based on comparison of calculation result with interpretation of test data, peat coefficient value used is 8%. Interpretation of test data tends to be closer to the cylindrical shear method with a standard error of 0.74 than the individual bearing method with standard error of 1.03.Keywords: Helical Pile, Peat Soil, Individual Bearing, Cylindrical Shear
Pengaruh Waktu Curing Terhadap Nilai Swelling Pada Tanah Lempung Dengan Campuran Fly Ash Dan Bottom Ash Lembasi, Muhammad Khadafi; Nugroho, Soewignjo Agus; Fatnanta, Ferry
Dinamika Rekayasa Vol 17, No 1 (2021): Jurnal Ilmiah Dinamika Rekayasa - Februari 2021
Publisher : Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.dr.2021.17.1.346

Abstract

Tanah lempung yang berplastisitaas tinggi memiliki masalah dengan kembang susut yang cukup tinggi, oleh karena itu perlu adanya stabilisasi agar nilai pengembangan pada tanah lempung plastisitas tinggi turun dan dapat digunakan sebagai tanah dasar dalam suatu konstuksi. Upaya stabilisasi yang dilakukan dengan dengan cara mencampurkan tanah lempung dengan bahan adiktif berupa abu dasar, abu terbang, dan kapur. Tujuan penelitian ini adalah untuk mengetahui pengaruh lama waktu pemeraman untuk mendapatkan nilai pengembangan terkecil pada tanah lempung plastisitas tinggi akibat penambahan bahan adiktif berupa kapur, abu dasar dan abu terbang. Hasil menunjukan bahwa dengan penambahan bahan adiktif dan memberi perlakuan berupa pemeraman pada campuran tanah lempung dapat menurunkan nilai swelling. Untuk kondisi optimum potensi pengembangan terjadi pada variasi campuran L 5% + MS6 95%, dimana pada campuran tersebut potensi pengembangan sangat kecil dibandingkan dengan tanah asli dan tanah campuran lainnya. Dapat dilihat dari kondisi pemeraman 28 hari penurunan yang terjadi sebesar 98% dibanding tanah asli yang tidak diberi perlakuan. Jadi, dapat disimpulkan dengan memberi campuran bahan adiktif dan diberi pemeraman dapat memperbaiki tanah asli dan dapat memperkecil nilai swelling potential
Pengaruh Jarak Antar Fondasi Dan Kekasaran Terhadap Daya Dukung Fondasi Tiang Kelompok Sayoga, Davin; Fatnanta, Ferry; Nugroho, Soewignjo Agus
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 7 (2020): Edisi 2 Juli s/d Desember 2020
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains

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Abstract

Upper soil crust of coastal area in Indonesia consists of greatly-thick soft soil. Therefore, the use of end-bearing type pile foundation on that kind of area is highly discouraged due to how expensive it is economically. Friction pile becomes an alternative foundation for coastal area, however there is still little friction between pile surface and soil due to concrete and steel’s smooth surface. Pile modification via improving pile surface’s coarseness can be considered as an alternative for improving friction force between pile and soil. This study aims to determine the effect of pile surface coarseness towards pile surface’s bearing capacity. This study was conducted by making a varying type of coarseness of the pile surface and distance between piles. The first type of coarseness is matched with pile with concrete ingredient. The second type of coarseness is made with stone shards which cover the pile surface in its entirety. The third type of coarseness is a variance of how the first and second coarseness are made, however with same length between segments. The observation was conducted in a laboratory and with loading test applied on the pile model. The test results were analyzed with graphic method. The resulting study shows that there is an improvement in bearing capacity. Foundation with coarseness on its surface has higher Qult value (98,03% - 134,63%) than those without coarseness. Keywords : Soft Soil, Pile Foundation, Coarseness, Static Loading Test, Interpretation of Loading Test
Analisis Perkuatan Lereng Menggunakan Finite Element Method Ongko, Andarsin; Nugroho, Soewignjo Agus; Yusa, Muhamad
Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains Vol 5 (2018): Edisi 2 Juli s/d Desember 2018
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Teknik dan Sains

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Abstract

Landslides are ones of disasters which oftenly occurred in Indonesia. This research aims to analyze some slope reinforcements which are modeled by using a based finite element method software, i.e. plaxis v.8.2. As initial data, slope`s dimension was measured from real field, and soil samples were taken to obtain the soil properties. Those data were used as input parameters in modeling. The slope was modeled in several conditions, i.e. existing condition, variation of ground water table, reinforcement with backfill model, terraces model, and soil nailing model. The results shown that safety factor has decreased due to the increment of ground water table. The highest safety factor was reached when the slope was reinforced with soil noiling model, with the magnitude of 2,044.Keywords : landslides, finite element method, soil nailing, safety factor.
Estimation of standard penetration test value on cohesive soil using artificial neural network without data normalization Soewignjo Agus Nugroho; Hendra Fernando; Reni Suryanita
IAES International Journal of Artificial Intelligence (IJ-AI) Vol 11, No 1: March 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijai.v11.i1.pp210-220

Abstract

Artificial neural networks (ANNs) are often used recently by researchers to solve complex and nonlinear problems. Standard penetration test (SPT) and cone penetration test (CPT) are field tests that are often used to obtain soil parameters. There have been many previous studies that examined the value obtained through the SPT test with the CPT test, but the research carried out still uses equations that are linear. This research will conduct an estimated value of SPT on cohesive soil using CPT data in the form of end resistance and blanket resistance, and laboratory test data such as effective overburden pressure, liquid limit, plastic limit and percentage of sand, silt and clay. This study used 242 data with testing areas in several cities on the island of Sumatra, Indonesia. The developed artificial neural network will be created without data normalization. The final results of this study are in the form of root mean square error (RMSE) values 3.441, mean absolute error (MAE) 2.318 and R2 0.9451 for training data and RMSE 2.785, MAE 2.085, R2 0.9792 for test data. The RMSE, MAE and R2 values in this study indicate that the ANN that has been developed is considered quite good and efficient in estimating the SPT value.
Pengaruh Abu Sekam Kayu Pada Nilai Unconfined Compression Strength Lempung Plastisitas Tinggi Terstabilisasi Semen Kapur Soewignjo Agus NUGROHO; Muhammad Faisal Al Ridho; Ferry Fatnanta
TERAS JURNAL Vol 12, No 1 (2022): Volume 12 Nomor 1, Maret 2022
Publisher : UNIVERSITAS MALIKUSSALEH

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29103/tj.v12i1.688

Abstract

Abstrak Perbaikan lempung dengan semen, kapur, dan abu sekam (RHA) terbukti meningkatkan kuat geser dan daya dukung. Kandungan silika abu sekam kayu (ASK) hampir sama dengan RHA. Penelitian melihat pengaruh ASK pada lempung terstabilisasi semen dan kapur. Pengujian Tekan bebas (UCS) dilakukan untuk membandingkan nilai kuat tekan bebas (qu) lempung asli, lempung distabilisasi semen, dan kombinasi semen dan kapur dan/atau ASK. Sampel diuji pada empat kondisi. Hasil UCS tanpa pemeraman, nilai qu seragam. Pada kondisi tanpa pemeraman dan perendaman, nilai qu semua variasi relatif sama. Pada kondisi pemeraman dan tanpa perendaman, nilai qu berkisar 365 kPa sampai dengan 485 kPa untuk campuran dengan ASK dan kombinasi kapur dengan ASK. Penambahan kapur 10% meningkatkan nilai qu lebih 1100 kPa. Hasil UCS membuktikan, kapur lebih optimal meningkatkan nilai qu dibanding ASK. Penggantian kapur dengan ASK 4% sampai 6% meningkatkan nilai qu menjadi 485 kPa (rendaman) dan menjadi 475 kPa (tanpa rendaman). Kata kunci: Abu sekam Kayu, Kapur, lempung, semen, stabilisasi  Abstract Clay stabilized with cement, lime, and rice hush ash (RHA) has been increasing shear strength and bearing capacity. The silica content of wood husk ash (ASK) is almost the same as RHA. The study seen effect of ASK on clay-cement and lime. Unconfined Compression Strength (UCS) is performed and compare unconfining strength values (qu) of clay, clay-cement, and cement and lime and/or ASK. Sampel was tested on four conditions. UCS results without watering, uniform qu value. Conditions non-curing and soaked, the qu values of all variations are relatively the same. In curing and unsoaked conditions, qu values range from 365 kPa to 485 kPa for ASK and lime with ASK. Adding 10% lime increases qu value more than 1100 kPa. Stabilized with lime is more optimal than ASK to increase qu. Subtitution lime with ASK 4% to 6% increases qu value to 485 kPa (soaked) and to 475 kPa (unsoaked). Keywords: clay, cement, lime, sawdust ash, stabilization 
Prediction of SPT value based on CPT data and soil properties using ANN with and without normalization Hendra Fernando; Soewignjo Agus Nugroho; Reni Suryanita; Mamoru Kikumoto
International Journal of Artificial Intelligence Research Vol 5, No 2 (2021): December 2021
Publisher : STMIK Dharma Wacana

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (445.835 KB) | DOI: 10.29099/ijair.v5i2.208

Abstract

Artificial neural networks (ANN) are now widely used and are becoming popular among researchers, especially in the geotechnical field. In general, data normalization is carried out to make ANN whose range is in accordance with the activation function used. Other studies have tried to create an ANN without normalizing the data and ANN is considered capable of making predictions. In this study, a comparison of ANN with and without data normalization was carried out in predicting SPT values based on CPT data and soil physical properties on cohesive soils. The input data used in this study are the value of tip resistance, sleeve resistance, effective soil overburden pressure, liquid limit, plastic limit and percentage of sand, silt and clay. The results showed that the ANN was able to make predictions effectively both on networks with and without data normalization. In this study, it was found that the ANN without data normalization showed a smaller error value than the ANN with data normalization. In the network model without data normalization, RMSE values were 3.024, MAE 1.822, R2 0.952 on the training data and RMSE 2.163, MAE 1.233 and R2 0.976 on the test data. Whereas in the ANN with data normalization, the RMSE values were 3.441, MAE 2.318, R2 0.936 in the training data and RMSE 2.785, MAE 2.085 and R2 0.963 in the test data. ANN with normalization provides a simpler architecture, which only requires 1 hidden layer compared to ANN without normalization which requires 2 hidden layer architecture.
PERUBAHAN NILAI CBR TERHADAP PENAMBAHAN FLY ASH DAN BATTOM ASH PADA TANAH LEMPUNG Soewignjo Agus Nugroho; Ferry Fatnanta; Muhammad Khadafi Lembasi
Rekayasa Sipil Vol. 16 No. 1 (2022): Rekayasa Sipil Vol.16. No.1
Publisher : Department of Civil Engineering, Faculty of Engineering, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.rekayasasipil.2022.016.01.3

Abstract

Clay soil has a characteristic that is wet, it will be soft and plastic and cohesive. To overcome this problem, clay soil with high plasticity needs stabilization. The stabilization method using additives such as chalk, fly ash and bottom ash can be used as a stabilization material to increase the carrying capacity of high plasticity clay. This study is commended to know the behavior of high plasticity clay which is stabilized with lime, fly ash and bottom ash. Increased crease of the stabilized clay soil is seen from the CBR test. CBR testing is done under curing conditions for 0, 14, and 28 days and soaking for 0 and 4 days. The results showed that the CBR value increased with duration of curing and decreased throughout the duration of immersion. Then the CBR value increases with the addition of lime percentage and each mixture in a mixture variation. The highest CBR value occurred in soil L 5% + MS5 95% with a CBR value of 75.37% under conditions for 28 days of curing and 4 days of immersion. The lowest CBR value occurs in soil L 5% + MS2 95% with a CBR value of 12.85% in conditions without curing and without immersion.
Prediction of standard penetration test value on cohesive soil using artificial neural networks Soewignjo Agus Nugroho; Hendra Fernando; Reni Suryanita
Jurnal Informatika Vol 15, No 2 (2021): May 2021
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/jifo.v15i2.a19822

Abstract

Soil investigation is the main key in starting construction. Standard Penetration Test (SPT) and Cone Penetration Test (CPT) are field tests often used to estimate soil parameters for foundation design purposes. The SPT value (N-SPT) shows a correlation between the CPT value and other soil parameters. At present, there have been many conventional correlations examining these correlations, but the nonlinear nature of the soil due to very complex soil formations means that this correlation cannot be used in all situations. This research aimed to predict the value of SPT on cohesive soil based on CPT test data and soil physical properties using artificial neural network capabilities using the Backpropagation algorithm, and the activation function was bipolar sigmoid. This study used 284 data from several places in Sumatra Island, Indonesia, with data input were tip resistance, shaft resistance, effective overburden pressure, percentage of liquid limit, plastic limit, sand, silt, and clay. The results showed that the training data of RMSE was 3.441, MAE and R2 were 0.9451 and 2.318, respectively while test data showed RMSE, MAE, R2 were 2.785, 2.085, and 0.9792, respectively. It means that the proposed artificial neural network NN_Nspt(C) was promising to predict the N-SPT value with a minimum error value and a strong regression equation.