Indonesia's peatlands are concentrated in three major islands, namely Sumatra (35%), Kalimantan (... more Indonesia's peatlands are concentrated in three major islands, namely Sumatra (35%), Kalimantan (32%), Papua (30%), and other islands (3%) of a total area of 21 million ha. Peat has a low carrying capacity. The carrying capacity of the soil is largely determined by the value of the water content contained in the peat. To overcome this problem, stabilization is carried out using a mixture of biopolymers to increase the carrying capacity of the soil. In this study, testing of the physical properties of peat soil was carried out in order to determine changes in the value of the physical properties of the soil that occurred after stabilization. The sampling location is in the area of Palangka Raya City. There were 5 variations of samples made for stabilizing peat soil with a mixture of 0.5%, 1%, 2%, 2.5%, and 3% biopolymer. The final results obtained after testing the physical properties of post-stabilization peat soil were a decrease in water content in the 3% biopolymer (395.13%) variation, the maximum decrease in fiber content in the 3% biopolymer (30.79%), and the maximum ash content obtained in the 3% biopolymer increasing the value of the bulk density at 3% bipolymer (1.64%), and increasing organic content (96.62%) at 3% biopolymer variation.
Peat soils are organic soils formed from decomposed plant parts that spread throughout the world,... more Peat soils are organic soils formed from decomposed plant parts that spread throughout the world, reaching 423 million hectares. It is well known that peat soils have adverse characteristics for infrastructure development due to their low shear strength and durability. Therefore, a lot of research has been done regarding the improvement of peat soils so that infrastructure development in dominant peat soil locations. However, in conducting the research, many tests were found to be inappropriate based on the characteristics of peat soils, causing doubts about the results of the research. In this paper, a literature study conducted based on books, journals, papers, or previous research to determine the characteristics of peat soils and the types of tests that are suitable for these characteristics. Based on the discussion, the physical properties of peat soil can be tested for ash content, fibre content, organic content, and acidity, while the Atterberg limits cannot be tested. In addition, for testing the mechanical properties of peat soil, the tests that can be carried out are the direct shear test, Rowe cell, and CBR test with notes.
Comparative analysis of laboratory unsoaked CBR values between micromaterials and limestone nanom... more Comparative analysis of laboratory unsoaked CBR values between micromaterials and limestone nanomaterials in expansive soil stabilization Análise comparativa dos valores de CBR não embebidos em laboratório entre micromateriais e nanomateriais de cal na estabilização de solos expansivos Análisis comparativo de valores CBR de laboratorio sin remojo entre micromateriales y nanomateriales de piedra caliza en la estabilización de suelos expansivos
Peat soil is formed through the accumulation of undecomposed plant organic matter, resulting in a... more Peat soil is formed through the accumulation of undecomposed plant organic matter, resulting in a high fiber content that leads to poor physical properties and low shear strength. Consequently, peat soil is identified as problematic and detrimental in infrastructure construction. One proposed method to improve its physical properties and enhance shear strength is biological soil stabilization through biotechnology, with bioaugmentation as an environmentally friendly alternative. The objective of this research is to accelerating the decomposition of peat fiber by Pseudomonas taiwanensis bacteria, thereby accelerating soil compaction and improving its physical properties and shear strength. The subject of this research is fibrous peat soil in Bereng Bengkel Village, Palangkaraya, Central Kalimantan. From the experimental results, it was found that the addition of 15% Pseudomonas taiwanensis bacteria to fibrous peat can significantly improve the physical properties and shear strength. Thus, Pseudomonas taiwanensis bacteria can be used as an environmentally friendly alternative to improve the geotechnical properties of fibrous peat.
Expansive soils are soils that have high shrinkage expansion. This condition is detrimental to bu... more Expansive soils are soils that have high shrinkage expansion. This condition is detrimental to buildings on it. Losses due to swelling and shrinkage in expansive soils require stabilization with quicklime with varying particle sizes of materials needed to reduce soil swelling and shrinkage. Stabilization with nano has been widely used. However, the procurement of nanomaterials is very expensive. Therefore, this paper will explain the effectiveness of micromaterials when compared to nanomaterials. The main focus that will be discussed in this paper is how the comparison of plasticity index (PI) values between micromaterials and quicklime nanomaterials on expansive soils. The research was conducted at the Bandung State Polytechnic Laboratory. This research uses a stabilization method by adding 2% lime per particle size. The procurement price of nanomaterial was Rp. 2,500,000 and micromaterial was Rp. 1,500,000. The plasticity index (PI) test results obtained are the original soil is 35.68%; mixed soil 2% micromaterial lime is 11.51%; and mixed soil 2% nanomaterial lime is 7.62%. The results of PI values < 12 both include low expansive, so the more effective result is the PI condition of adding 2% micromaterial lime with the procurement of cheaper prices.
Efforts are needed to accelerate the decomposition of peat fiber to reduce the fiber content thro... more Efforts are needed to accelerate the decomposition of peat fiber to reduce the fiber content through bioaugmentation using Pseudomonas taiwanensis bacteria so that it can reduce the high-water content of peat fiber. The research aimed to determine the effect of adding Pseudomonas taiwanensis bacteria on the decomposition of peat fiber. This research is a laboratory experimental research. The research sampling location was in Bereng Bengkel Village, Palangkaraya. The parameters observed included fiber content, fiber size distribution, and peat fiber decomposition speed following the Peat Testing Manual. The research instrument was an observation sheet for fiber content, size distribution, and peat fiber decomposition speed. Research data was analyzed using descriptive statistical analysis. The results showed that adding 15% Pseudomonas taiwanensis bacteria with a curing period of 28 days in fibrous peat resulted in the highest reduction in fiber content, from the initial condition of 61.14% to 12.33%. This variation also shows a decrease in coarse and medium fiber content and a significant increase in fine fiber content. The decomposition rate for this variation shows good consistency. The conclusion was that adding 15% Pseudomonas taiwanensis bacteria with a curing period of 28 days showed optimal results in accelerating the decomposition of peat fiber through the bioaugmentation method.
This paper presents the potential of polyacrylamide (PAM) polymer to reduce cracking during wetti... more This paper presents the potential of polyacrylamide (PAM) polymer to reduce cracking during wetting-drying cycles. Several experiments have been conducted to investigate PAM polymer in high plasticity silt soils to reduce soil cracks and increase soil strength properties. In this study, Polymer was mixed in soil with different PAM variations (0.2%; 0.4%; 0.6%, 0,8% and 1% by weight). The behaviour of each soil sample was measured by a thermal imaging technique and confirmed by microstructural analysis. The patterns of the soils captured by the camera were quantified using image processing. The experimental results show more cracks in the initial soils than in treated soils. This was confirmed by the SEM test, which showed pores of soil particles. The results also show the role of PMA in reducing the initial void ratio could lead to an increase in bearing capacity. The interaction between PAM and soil particles could also reduce the crack potential. This is because there is solid bonding within soil mass after PAM treatment. In general, this study demonstrates the potential of PAM to reduce cracking and increase soil strength, as well as bring new insights into the design and assessment of sustainable infrastructure under climate change.
Tanggal 9 Januari 2021, terlah terjadi bencana alam tanah longsor terjadi di Dusun BojongKondang,... more Tanggal 9 Januari 2021, terlah terjadi bencana alam tanah longsor terjadi di Dusun BojongKondang, Desa Cihanjuang, Kec. Cimanggung, Kab. Sumedang. Keberadaanya masyarakat di zona merah sangat berbahaya. Ditambah dengan kondisi lereng yang relative curam sehingga perlu dilakukan studi terhadap stabiltas lereng untuk mengetahui faktor keamanan (SF) dari lereng tersebut. Pemukiman disekitar lokasi bencana alam tanah longsor dapat dikatakan aman jika nilai factor keamanan (safety factor) lerengnya >1,5. Dilakukan analisis terhadap pemodelan keretakan tanah untuk mendapatkan faktor keamanan terkritis di mana tanah dimodelkan sebagai tanah pasir (behaving like sand). Hal ini dapat diselesaikan dengan mengaplikasikan The Concept of Cracked Soil. Penelitian mengenai keretakan tanah baru dilakukan 10 tahun terakhir. Selanjutnya dilakukan penelitian dengan melakukan kajian lapangan untuk menemukan posisi retakan di lereng, dan pada tahun 2020 dilakukan pemodelan analisis numeric untuk stabilitas lereng dalam kondisi retak.
Penerapan Konsep Baru Cracked Soils Pada Penangulangan Kelongsoran Lereng (Studi Kasus : Pembangunan Gedung Reskrimsus Polda Kalimantan Timur, Balikpapan)
Hasil analisa stabilitas lereng dengan tanah cukup kaku didasarkan pada kondisi terekstrim yaitu ... more Hasil analisa stabilitas lereng dengan tanah cukup kaku didasarkan pada kondisi terekstrim yaitu kondisi saturated akibat hujan dari lereng di area pembangunan gedung Reskrimsus Polda Kalimantan Timur, Balikpapan menunjukkan angka keamanan, SF>1. Hal ini berarti lereng tersebut kondisi aman walaupun ketika terjadi hujan. Pada kenyataannya, setelah lereng diguyur hujan dengan intensitas sangat lebat, lereng bergerak yang mengakibatkan kerusakan struktur di sekitarnya. Fenomena ini dapat dijawab dengan the concept of cracked soil yang mengakomodir keberadaan retak pada lereng dan pengaruh intensitas hujan yang belum banyak diperhatikan dalam menganalisa stabilitas lereng sampai saat ini. Retakan yang terinfiltrasi air hujan pada saat hujan sangat lebat akan menentukan stabilitas lereng. Parameter pada retakan ini berbeda dengan parameter tanah utuh dimana tanah tersebut dianggap berperilaku seperti pasir (c=0 dan f≠0) dan pada retakan tersebut akan terbentuk pore water pressure bui...
Kajian Mengenai Persyaratan Agar Pondasi Raft Dan Pile Mampu Berkerja Sebagai Sistem Pile Raft
Kajian Mengenai Persyaratan Agar Pondasi Raft Dan Pile Mampu Berkerja Sebagai Sistem Pile Raft, Aug 19, 2010
Banyak bangunan-bangunan di Indonesia yang dibangun di atas tanah lunak (compressible soil) mengg... more Banyak bangunan-bangunan di Indonesia yang dibangun di atas tanah lunak (compressible soil) menggunakan tiang pancang end bearing sebagai pondasinya untuk mengatasi permasalahan akibat daya dukung yang rendah dan pemampatan yang besar. Hal itu mengakibatkan biaya yang sangat besar mengingat banyak tanah keras di Indonesia baru dijumpai dikedalaman 40 m bahkan lebih. Solusi selama ini adalah menggunakan pondasi tiang floating. Penggunaan pondasi ini seringkali dipermasalahkan, apakah kontribusi raft diperhitungkan atau tidak. Jika kontribusi raft diperhitungkan berarti merrupakan sebuah pile-raft systems yang perlu dikaji lebih lanjut mengenai batasannya. Untuk itu diambil berbagai jenis compressible soil dari 10 titik bor di teluk lamong, dimana tiap titiknya dibor sampai kedalaman 60 m. Data-data yang diperoleh dari lokasi tersebut dianalisis hingga menghasilkan 3 variasi jenis tanah (very soft clay, soft clay, dan medium clay). Untuk data-data tanah yang tidak diketahui (seperti E dan ν) diambil dari tabel-tabel korelasi yang ada. Sistem pile raft yang telah ditentukan sebelumnya dihitung secara manual (Poulos, 1980) dan dimodelkan pada program finite element 3D, Plaxis versi 1.6 sebagai pembanding. Sebelum pemodelan Pile raft systems dalam Plaxis, dilakukan validasi data-data masukkan dengan membandingkan hasil keluaran program plaxis dan hasil perhitungan pondasi raft secara manual. Setelah hasil validasi dinyatakan sesuai (perbedaan nilainya dibawah 20%) barulah dilakukan pemodelan pile raft systems dan end bearing pile dengan menggunakan Plaxis dengan variasi 3 jenis tanah, 3 macam ketebalan raft, 4 macam jumlah tiang, dan variasi panjang tiang. Dari hasil secara garis besar didapatkan bahwa sistem pile raft ini terbukti lebih bisa mereduksi settlement dari pada sistem tiang murni. Pada sistem ini semakin kaku jenis tanah penurunan yang didapatkan semakin kecil. Dengan semakin tebalnya raft dan semakin kakunya tanah mengakibatkan differential settlement dan momen yang terjadi pada raft semakin kecil. Sistem pondasi raft pile berfungsi jika panjang tiang lebih kecil dari panjang tiang untuk mencapai daya dukung ultimate (panjang tiang ultimate), dimana panjang tiang ultimate ini cenderung tergantung pada beban yang bekerja dan jenis tanah. Hasil pemodelan Plaxis pada very soft clay menunjukkan hasil yang berbeda, hal ini dimungkinkan karena pemilihan penggunaan material mohr coulomb yang kurang mewakili kondisi tanah very soft clay, pengambilan nilai-nilai parameter E dan ν yang kurang sesuai, dan tidak memperhitungkan waktu dalam pentahapan pelaksanaan.
Jalan Cisasawi mengalami kelongsoran pada tahun 2020. Usaha penanganan kelongsoran telah dilakuka... more Jalan Cisasawi mengalami kelongsoran pada tahun 2020. Usaha penanganan kelongsoran telah dilakukan oleh warga, menggunakan Bronjong. Hanya saja, perencanaan perkuatan tersebut tidak memperhitungkan persyaratan yang berlaku. Agar tidak terjadi kejadian serupa, perlu dilakukan evaluasi terhadap perkuatan tersebut. Evaluasi dimulai dengan pengumpulkan data dengan cara pengukuran geometri lereng dan pengujian tanah. Analisis stabilitas dilakukan menggunakan software Geostudio. Evaluasi dilakukan di akhir untuk mengetahui apakah konstruksi perkuatan lereng eksisting tersebut cukup aman atau tidak. Dari hasil analisis didapatkan bahwa nilai SF dari lereng eksisting (sebelum adanya bronjong) sebesar 0,504. Kondisi ini sesuai dengan lapangan yaitu lereng mengalami kelongsoran. Hasil analisis stabilitas lereng setelah diperkuat dengan Bronjong adalah SF sebesar 1,014. Nilai SF ini tidak memenuhi yang disyaratkan SNI 8460-2017 faktor keamanan dalam kondisi gempa SF lebih besar dari 1,1 sehingga diperlukan alternatif perkuatan tambahan lereng. Alternatif perkuatan tambahan lereng dilakukan memperbesar dimensi bronjong. Dari hasil analisis perkuatan tambahan didapatkan SF sebesar 1,277.
Proceedings of the 2nd International Seminar of Science and Applied Technology (ISSAT 2021), 2021
The distribution of soft and expansive soil that is often found in Indonesia often causes problem... more The distribution of soft and expansive soil that is often found in Indonesia often causes problems in the structure above it. To build the infrastructure on expansive soil, it is necessary to improve the subgrade. One method to improve soil is to stabilize it by using biopolymers. Biopolymer was chosen because it is more environmentally friendly than the use of cement as soil stabilization. In this study, Xanthan Gum (XG) biopolymer was used, with concentrations of 1%, 2%, and 4%. Testing was carried out experimentally in the form of testing physical and mechanical properties as well as cyclic drying testing. From the results of the analysis, the XG biopolymer can reduce the number and width of cracks after experiencing a drastic reduction in water content. A positive impact was also obtained on the mechanical analysis with the addition of biopolymers that could increase the compressive strength of the soil up to 432% and the shear strength of the soil up to 482%.
Many studies have begun to develop the concept of cracked soil. The results of research related t... more Many studies have begun to develop the concept of cracked soil. The results of research related to cracked soil are able to answer the irregularities that occur, such as the difference in the results of the stability analysis which is considered safe with the conventional bishop method, while the conditions in the field are landslides. Swelling soil is soil that is susceptible to changes in water content. This type of soil is very prone to cracking. To build infrastructure on the swelling soil type, an improvement must be made, one of which is by mixing the swelling soil with biopolymer. The results of this biopolymer mixing are then modeled in the New Slope Stability Analysis Program (NSSAP) 1.0 which refers to the concept of cracked soil. From the analysis, it was found that the slope safety factor before improvement with biopolymer was 0.305 and the safety factor after improvement with biopolymer was 2.006. From the results of this study, it can be seen that the role of biopolyme...
In the concept of cracked soils, one of the important factors for determining slope stability is ... more In the concept of cracked soils, one of the important factors for determining slope stability is the position of cracks. The position of cracks has been successfully obtained by other study using geoelectric testing. The geoelectric data produces several colors that describe the conditions of the slope geometry, soil stratigraphy, and the position of the cracks inside the slope. In order to improve the accuracy of reading geoelectric data for slope stability analysis, a digital image processing technique is proposed here. This digital image technology is applied by means of an auxiliary program based on the graphical user interface (GUI) that exists inside the MATLAB m-files and utilizing the option of RGB (Red, Green, Blue) color formats. With this technique, geoelectric data retrieval will take place automatically, thus it can be directly used as input for the slope stability analysis program to determine the value of the slope safety factor. The image processing technique in this study is based on using a straight-line equation to detect slope geometry, soil stratigraphy, and the position of cracks on slopes based on the geoelectric data. The simulation results in this study provide sufficiently accurate values of geoelectric data retrieval, which is to reach 5.78 cm/pixel. The larger the pixel size of the processed slope image, the higher the accuracy of the program outcomes. The results of this study will be later used for input in the new slope stability analysis based on cracked soil approaches utilizing digital image technology.
alan Tol Pejagan-Pemalang merupakan bagian dari jaringan Jalan Tol Trans Jawa yang menjadisolusi ... more alan Tol Pejagan-Pemalang merupakan bagian dari jaringan Jalan Tol Trans Jawa yang menjadisolusi dari permasalahan kemacetan di Jalur Pantai Utara (Pantura). Jalan Tol Pejagan -Pemalangberada di atas tanah lunak yang akan menimbulkan permasalahan geoteknik, seperti daya dukung tanahdasar yang rendah, stabilitas timbunan, dan penurunan yang besar serta berlangsung dalam jangkawaktu yang lama. Tanah dasar yang lunak tersebut tidak mampu untuk menahan beban total timbunanrencana yaitu 8,9 m. Tinggi timbunan maksimum yang mampu ditahan oleh tanah dasar tersebut adalah5 m. Dengan memperhatikan penurunan total yang terjadi, tinggi timbunan pada saat pelaksanaan haruslebih tinggi dari tinggi timbunan rencana. Tinggi timbunan pada saat pelaksanaan akhir adalah 11 mdengan penurunan total yang terjadi sebesar 2,122 m dalam waktu 38,49 tahun. Masalah ini dapatdiatasi dengan memperbaiki tanah dasar menggunakan PVD yang dioptimalkan dengan preloading.PVD adalah lembaran plastik untuk drainase ve...
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