Browsing by Author "Sandyavitri, Ari"

Now showing 1 - 15 of 15
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    Analisa Resiko Pembangunan Proyek Konstruksi Di Pedesaan (Studi Kasus: Pembangunan Infrastruktur Air Bersih Dan Transportasi)
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari
    Cost escalation may occur in the implementation of any construction projects caused by failure in the identification, analysis and mitigation of risks and their negative impacts. Two case studies concerning risk analysis in the development of water supply project and transportation project were presented to demonstrate the role of risk analysis can play in managing and reducing project risks. It is identified thay 9 risks were emerged in the implementation of the water supply project in Padang City, West Sumatra, and 5 risks were occurred in the construction phase of the bridge in Kelayang, Indragiri Hulu, Riau. This analysis quantifies the effects of identified risks on economic parameters. After risks analysis has been applied, the projects may appear more risky. This is because the identified negative risks have not been mitigated. Thus, the negative risks often outweigh the positive risks. The cumulative negative effects of the risks have suffered project contractor and project operator in terms of economic parameters (Net Present Vaue, NPV, Internal Rate of Return, IRR and Cash Pay Back Time, CBT). By the identification, analysis and mitigating various parameters of the risks using Caspar and @Risk for Project software package, there were probability to improve projects paramenters within these two projects by 50%-100% before and after risk mitigation procedure apllied.
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    Analisis Risiko Pembangunan Jalan Tol Pada Tahap Konstruksi (Studi Kasus Jalan Tol Pekanbaru-Dumai)
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari; Zulfiqar, Muhammad
    Ruas Jalan yng menghubungkan antara Kota Pekanbaru-Dumai (terdiri dari 2-lajur 2-arah) adalah merupakan urat nadi transportasi penting di Provinsi Riau. Diproyeksikan ruas jalan ini akan over kapasitas pada tahun 2015. Oleh karena itu direncanakan akan diabgun jalan tol untuk mengatasi masalah tersebut. Namun, investasi untuk pembangunan jalan tol melibatkan beberapa tingkat risiko dan ketidakpastian, maka analisis dan pengelolaan risiko diperlukan dalam proses pembangunan jalan tol ini. Tujuan dari penelitian ini adalah untuk mengidentifikasi dan menganalisis risiko proyek (selama proyek tahap konstruksi). Studi ini mengukur nilai probabilitas risiko dan dampak risiko yang mungkin terjadi selama tahap konstruksi jalan tol. Besarnya masing-masing risiko dianalisis dan disimulasikan menggunakan perangkat lunak @ Risk. Dalam rangka untuk mendapatkan input data, survei dilaksnakan dalam dua tahap utama; (i) survei awal, dan (ii) survei detil. Kemudian dilakukan analisis risiko berdasarkan stokastik. Hasil analisis kemudian dibandingkan dengan parameter-parameter risiko yang diterbitkan oleh Puslitbang Pd-T-01-2005-B 2005. Diidentifikasi empat risiko utama yang dipengaruhi selama tahap konstruksi proyek, sebagai berikut; (i) risiko pembiayaan proyek, (ii) risiko pembangunan proyek, (iii) risiko peralatan, dan (iv) force majeure. Besarnya risiko yang mungkin terjadi selama proyek konstruksi jalan tol ini diidentifikasi sebagai kategori risiko sedang, yang membutuhkan penanganan khusus.
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    Aplikasi Metode Vertical Drain Untuk Stabilisasi Tanah Dasar Landasan Pacu Lapangan Terbang
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari; Wibisono, Gunawan
    The existing sub-grade of the Tampuling Airport runway in Tembilahan City, Riau Province is in the group of peat soil with the depth of more than 30 m. The compressibility rate type of this soft soil is very high. Based on “the worst case scenario” without any soil stabilization treatment, it was estimated that the soil consolidation rate would reach 1.7 metres, within 20 years of period of settlement time. In order to speed up its consolidation process to stabilizing the soil (for becoming a sub-grade the run way), the vertical drain method was applied. The procedures for designing of pre loading for the soil, as well as the calculation of the distance between vertical drains are then demonstrated in this paper. It was recommended that the depth of the designed vertical drain would be 18 metres, with the distance between the vertical drains is 1.2 metres each; height of the soil pre loading is 4.5 metres. With these design parameters, it was expected that the settlement process would be accelerated by 40 folds (235 months to become 6 months period).
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    Developing And Selecting Slope Stabilization Techniques In Managing Slope Failures
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari
    This paper objectives are to; (i) identification of risky slopes (within 4 Provinces in Sumatra including Provinces of Riau, West Sumatra, Jambi and South Sumatra encompassing 840 kms of the “Jalan Lintas Sumatra” highway) based on Rockfall Hazard Rating Systems (RHRS) method; (ii) developing alternatives to stabilize slope hazards, and (iii) selecting appropriate slopes stabilization techniques based on both proactive approach and value engineering one. Based on the Rockfall Hazard Rating Systems (RHRS) method, it was identified 109 steep slopes prone to failure within this highway section. Approximately, 15 slopes were identified as potential high-risk slopes (RHRS scores were calculated >200 points). Based on the proactive approach, seven riskiest slopes ware identified. The preferred stabilization alternatives to remedy most of these slopes are suggested as follow; either (i) a combination of retaining wall and drainage, or (ii) gabion structure and drainage. However, different approaches may yield different results, there are at least 2 main consideration in prioritizing slope stabilization; (i) based on the riskiest slopes, and (ii) the least expensive stabilization alternatives.
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    Investigasi Tingkat Kerawan Lereng Untuk Penyusunan Strategi Penanganan Jalan Dan Lereng (Studi Jalan Lintas Tengah Sumatera)
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari; Helmi, Achmad
    Highway embankments and slopes are critical supporting transportation systems to function effectively. Investigation of rockfall hazards (as well as managing highway embankments and slopes) are crucial reducing risk hazards impose to highway users to red. The research aims to identify highway slopes prone to rockfall, based on the Rockfall Hazard Rating System (RHRS) on the highway sections Pekanbaru (Riau) - Taluk Kuantan (Riau) – Kiliran Jao (Riau) –Dharmasraya (Sumatera Barat), Muaro Bungo (Sumatera Barat) - Sarolangun (Jambi) – Lubuk Linggau (Jambi) – Lahat (Sumatera Selatan) (837 km). It was identified, 109 slopes prone to rockfal. Of which 15 slopes were classified as potentially rockfall hazard ones. There were three the highest score of RHRS slopes are as follow; RHRS of 475 (Slope at KM 609.2), RHRS 451 (at KM 136), RHRS 413 (KM 215.5) respectively. Various factors determine the hazard scores are as follow; slope heights, ditches, highway wide, average vehicle risks (AVR), block sizes, and rockfall history. The investigation may assist decision makers to develop strategy in managing highways and slopes within Sumatra Island enhancing transportation safety for road users
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    Major Threats and Strategy for Sustainability of Water Supply Industry Operation (Case Study in Indonesia)
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari
    Various threats in the operation of water supply industry (PDAMs) in Indonesia were identified, this paper highlighted six major threats, they may include; limited scale of PDAMs service coverage; limited access to capital investment; low water tariff and poor cost recovery to pay debts and project operation; poor staff performances, high levels of unaccounted for water, and political as well as environmental risks. Strategic plans for mitigation of the threats were proposed at three levels of authority: (i) at the Central Government level; (ii) local/regional governments; and (iii) water utilities. By understanding the nature of the PDAMs threats, and better preparation of holistic strategy for managing the identified threats at various governmental levels, it is expected that sustainability of PDAMs operation might be achieved systematically.
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    Mitigating of Rockfall Risks
    (wahyu sari yeni, 2018-09-04) Preh, Alexander; Sandyavitri, Ari
    Rockfall cases are a natural and dynamic geologic process, commonly occur within mountainous areas near by the cliffs undercut by human for developing building or highway. This paper simulated rockfall process within manmade slope in the quarry at the Kloch, Austria. This paper revealed 7 (seven) slope surface parameters for this slope, including; dynamic and static friction angles (350), normal and tangential damping (0.2 and 0.95 consecutively), rolling resistance (0.2 to 0.3), amplitude of roughness (0), and frequency of roughness (1). These results were than treated as an input data in the simulation of the designated rockfall. Based on the simulation results, it was identified that the Kloch slope height was 15 m, the rocfall would yield the kinetic energy of 240 kJ, and 0.5 m of bouncing height. Hence, in order to protect toe area from the rockfall risks, it is recommended to construct a minimum 1 m height of retaining wall with a capacity to restrain the rockfall kinetic energy up to 500 kJ as an appropriate barrier for this case
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    Pemetaan Tingkat Kerawan Lereng (Studi Kasus : Ruas Jalan Lintas Tengah Sumatera, 830 Km)
    (2018-09-04) Sandyavitri, Ari
    Geotechnical assets such as slopes, rock-cuts, retaining wall and embankments are as an important element supporting transportation systems. Investigation and mapping of numerous slopes (potential to failure) are crucial reducing risk hazards impose to highway users. The research aims are to investigate and mapping landslides or rockfalls hazard rating. The investigation method is based on the Rockfall Hazard Rating System (RHRS) developed by ODOT, 1996. The investigated slopes are located on the highway sections Pekanbaru (Riau) - Taluk Kuantan (Riau) – Kiliran Jao (Riau) –Dharmasraya (Sumatera Barat), Muaro Bungo (Sumatera Barat) - Sarolangun (Jambi) – Lubuk Linggau (Jambi) – Lahat (Sumatera Selatan) (830 km). It was identified, 109 slopes prone to rockfall. Of which 15 slopes were classified as potentially landslide/ rockfall hazard ones. There were three the highest score of RHRS slopes are as follow; RHRS of 475 (at KM 609.2), RHRS 451 (at KM 136), RHRS 413 (KM 215.5) respectively. Various factors determine the hazard scores are also identified such as; slope heights, ditches, highway wide, average vehicle risks (AVR), block sizes, precipitation, and rockfall history. Based on the RHRS method, the higher the RHRS scores, the more prioritized they are to remedy.
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    PEMILIHAN ALTERNATIF PERBAIKAN LERENG MELALUI PENDEKATAN “VALUE ENGINEERING”
    (2013-05-07) Sandyavitri, Ari; Taufik, Hendra
    Slope failures and rockfall present significant hazards, including damage to retaining walls, highway infrastructure, blocking of drainages, and loss of bridges infrastructures. There is a need decision support frameworks based on geotechnical asset management principles for effective slope remedy procedure. This research objectives are to; (i) identification the steep slopes prone to rockfall/erosion along Lintas Tengah Sumatra from Pekanbaru (Riau Province) – Solok (West Suatra Province) via “Jalur Lintas Tengah Sumatra highway” encompassing 260 Km; and (ii) developing technical approach to remedy the slopes and (iii) establishing procedure in prioritizing slopes remedy based on value engineering technique. This research identified 65 prone to erosion and rockfall events. Approximately, 15 slopes were identified as high-risk slopes with RHRS scores of >300 points. According to value engineering approach, technical and economical aspects shuld be put into consideration in order to address issues of highway safety in a systematic procedure as well as efficient in use of limited budgets. Value engineering approach may suggest to remedy slopes within this road section at the following order.
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    Pengembangan Kriteria-Kriteria Rencana Pemindahan Perkantoran Di Kota Pekanbaru Berdasarkan Ahp (Analytical Hierarchy Process)
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari; Ichsan, Rifky
    The Government of Pekanbaru City has planed to relocate the office centre to the sub-urban area in order to reduce the existing traffic congestion within the city centre zone and to make balance development between the city center and the sub-urban area. This study puts into account 3 alternative designated locations probably fit for the purpose. Those locations are (i) Jalan Palembang Kulim Tenayanraya District, (ii) Jalan Badak, Sail Tenayanraya District, and (iii) Jalan Lingkar Luar KIT, Okura, Rumbai Pesisir.District. Four major criteria have been developed as follow; physical criteria, accessibility criteria, infrastructures criteria, and environmental criteria. An Analytical Hierarchy Process (AHP) was implemented to analyze these criteria and the results were then compared to the results obtained from the Expert Choice software application package. It was revealed that the significant criteria are identified as the following order: (i) accessibility (42,5%), (ii) physical criteria (28,2%), (iii) infrastructure (21,3%), and (iv) environmental criteria (8,0%). It was recommended that the appropriate designated location for the office center as the following order; (i) first option is Jalan Badak, Tenayanraya (43,5%., (ii) second option is Jalan Palembang, Tenayanraya (42,0%), and (iii) third option is Jalan Lingkar Luar KIT, Okura (14,5%).
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    Pengendalian Dampak Perubahan Desain Terhadap Waktu Dan Biaya Pekerjaan Konstruksi
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari
    Perubahan signifikan pada struktur desain disaat fase konstruksi dapat berakibat fatal pada peningkatan biaya dan waktu pelaksanaan proyek. Tulisan ini mendemostrasikan pengaruh perubahan desain pada pembangunan gedung kantor Dewan Perwakilan Rakyat (DPR) Provinsi Riau. Perubahan desain struktur atap memicu dampak komulatif dari pelaksanan aktifitas pembangunan berupa perubahan dimensi rangka baja atap, struktur plafon, instalsi listrik dan perkabelan, dan penempatan ventilasi udara. Sebagai konsekuensinya proyek ini mengalami kelambatan sampai 68 hari dan peningkatan biaya sampai 29% dari total biaya (dari Rp. 57 miliar menjadi Rp. 73.3 miliar). Secara teoritis untuk mengurangi dampak kelambatan dan pembengkakan biaya proyek dapat diusulkan 4 (empat) metode pengendalian; (i) memanjemen kerja lembur; (ii) kerja bergantian; (iii) tambahan tenaga baru; dan (iv) pemindahan sebahagian tenaga dari kegiatan lain kerja bergiliran
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    People-Centred Approaches To Water And Environmental Sanitation Risk Management In Water Supply
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari
    It has been acknowledge that the decision-making process involved in water supply project appraisals have not been free of risks. In order to optimise project investments and resources in the context of objectives and targets, all financial, managerial and technical resources need to be systematically controlled through risk management procedures. It is essential to identify the most significant risks and apply the most effective mitigation measures. The CASPAR (Computer Aided Simulation for Project Appraisal and Review) Risk Management software package is applied to a case study project to evaluate the role that risk management can play in improving the commercial viability of water supply projects over extended project horizons (typically 25 years). Key risks are identified and the financial implications of risk mitigation measures for such risks are evaluated
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    Risk Analyses for Riau Regional Water Supply Projects (SPAM), Indonesia
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari
    This paper investigated to what extend risk analyses may play its role in the development of feasibility study of Riau regional water supply projects (regional SPAM). This SPAM services coverage area may cover 4 (four) regions in Riau province such as; Rokan Hulu regency, Rokan Hilir, Bengkalis and Dumai. The capacity of this SPAM is 500 l/second. Total financing required for development of this SPAM was approximately Rp. 344 billion. Project finance will be obtained from budget sharing scheme from APBN (Rp. 140 billion or 41%), APBD (Rp. 62 billion or 18%), and the private sector (Rp. 141 billion or 41%). Three stages of risk analyses have been applied in this paper, such as; (i) risk identification, (ii) risk assessment, and (iii) risk mitigation. Based on the simulation result, it was identified that the initial project NPV was in the rage of -Rp. 6.68 billion up to Rp. 18.01 billion. The mean value of the projected NPV was Rp. 6.27 billion. This project is considered to be risky to proceed, as there is 90% probability the projected NPV < Rp. 0. After risk mitigation procedure will be applied, there is a mean value of the project NPV is Rp. 9.9 billion (increase by 30% from the initial NPV). Four significant risk variables affected NPV performance are identified as follow; (i) engineering cost for constructing water treatment plant and facilities, (ii) cost of pipelines installation and accessories, (ii) electricity costs, and (iv) chemical cost expenditure. A reduction of technical uncertainties including design changes; redundant of engineering risk costs, introduction of energy efficient technology during project operation may reduce electricity and chemical costs. Hence, based on the simulation results, it is confirmed that, the risk analyses procedure may improve regional SPAM regional technical and economy performances (e.i. NPV parameters).
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    SISTEM PENGAMBILAN KEPUTUSAN (DECISSIONSUPPORT SYSTEM, DSS) PERBAIKAN DAN PEMELIHARAAN LERENG BERDASARKAN PROSEDUR MANAJEMEN ASET
    (2012-11-07) Sandyavitri, Ari; Muhardi; Burhanuddin; Sucipto Wijaya, Andi; Zulfi, Albert; Wibisono, Gunawan
    The simulation of Decision Support Systems (DSS) based on the Assets Management procedure (in managing rock slopes systematically) was demonstrated in this paper. Rock fall Hazard Rating System (RHRS) and Rock fall Mitigation Cost Estimate (RMCE) methods were applied in this paper to mapping, evaluate, and analyze rock fall hazard at the road section of Pekanbaru- Bukittinggi KM 75 to KM 115. Two major elements are subjects to investigate as follow; (i) technical aspect; and (ii) economy one. Based on the RHRS criteria, there should be the riskiest slopes and potential rock fall hazard be prioritized to be managed, they are slopes at KM 80.2 (left), KM 77 and KM 10.3 with RHRS values of 581, 542 and 420 points. The higher RHRS value of the slope the riskiest the slope to the road users. RMCE considers economy aspect to be put into consideration together with RHRS values. Cost estimate for managing rock fall is divided with RHRS is known as cost risk (CR). The CR may comprehensively assist process of DSS for managing the slopes within the road section above by offering flexible options such as; prioritizing the riskiest slopes with moderate CR values eg. Slopes of KM 109.3, KM 77 and KM 80.2 with the BR values of 200.000, 351.000, and 312.000 respectively; or prioritizing the rock fall hazard slopes with the lowest CR values (eg. CR below300.000) for slopes at KM. 109.5, 109.3, 112 dan 80.23.For the first option, it may yield 3 slopes can be repaired, and at second option it may repair 4 slopes.
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    A Systematic Approach for the Selection of Contract Strategies for Water Projects
    (wahyu sari yeni, 2018-09-04) Sandyavitri, Ari
    This paper describes the use of the ‘Pendulum Obligation Diagram’ (POD) and a set of ‘Assessment Criteria’ (AC) assisting decision-making process in selecting contract strategies for construction, operation and maintenance of new water supply projects in Padang City, Indonesia. The use of POD and AC are useful in comparing the relative merits of alternative contract strategies in the financing and developing of water supply projects. Various options were developed, it was summarized that a full concession contract will best meet most of the project requirements on fresh capital investment and is also attractive to investors as the projected IRR is relatively high (14.27%) and CPBT is relatively short (12.99 years) and a BOT contract strategy could meet partial project requirements with the IRR is 14.42% and CPBT is 10.41 years