KAJIAN RESIKO GEMPA DENGAN PENDEKATAN METODE RAPID VISUAL SCREENING (RVS) FEMA 154 DAN 3D RESPONSE SPEKTRUM TERHADAP GEDUNG UNIVERSITAS WIJAYAKUSUMA PURWOKERTO

Gempa merupakan salah satu yang terjadi akibat kejadian pergeseran tiba-tiba dari lapisan tanah di bawah permukaan bumi. Purwokerto sebagai kota Kabupaten Banyumas adalah kota yang saat ini berusaha berkembang seperti halnya kota-kota besar lainnya yang ada di Indonesia. Gedung perkuliahan merupakan fasilitas pelayanan umum dalam hal pendidikan terhadap masyarakat Sebagai gedung perkuliahan harus mampu memberikan kelayakan dan kenyamanan sehingga aktivitas di dalam dan luar gedung perkuliahan menjadi nyaman. Penelitian ini bertujuan meninjau kerentanan beberapa bangunan yang terdapat pada Universitas Wijayakusuma terhadap gempa bumi. Untuk mengetahui kelayakan bangunan tersebut pendekatan analisa yang dilakukan dengan menggunakan metode RVS yang terdapat pada FEMA 154, selain itu perhitungan pembebanan dilakukan dengan pemodelan SAP 2000 dengan metode 3D Response Spektrum. Hasil penelitian menunjukkan bahwa gedung bertingkat pada Universitas Wijayakusuma Purwokerto aman terhadap gempa apabila dikaji dengan metode RVS, sedangkan apabila dikaji dengan metode 3D response spectrum yang sesuai dengan SNI 1726-2019 gedung-gedung tersebut kurang aman untuk waktu getar alami fundamental, tetapi untuk pembebanan ketiga gedung tersebut aman.

Comparison of CSV-1000 and Metrovision contrast sensitivity tests in normal eyes

Background: Measuring contrast sensitivity (CS) allows a better understanding of the visual performance of the human eye. This study aimed to examine the correlation and agreement between the results of two sinewave grating-based CS measurement methods, Metrovision and CSV-1000, in normal eyes. Methods: This cross-sectional, comparative study was performed between December 2018 and April 2019, at an optometry clinic. Subjects underwent comprehensive ocular examinations, which included pupil reflexes, subjective refraction, external eye examinations, smooth pursuit eye movement assessment, the cover–uncover test, and detailed slit-lamp examination of the anterior and posterior segments. Metrovision and CSV-1000 were employed to assess CS under photopic conditions. The correlation and agreement of the results of the two tests were evaluated. Results: CS was measured for 104 normal eyes for 3, 6, 12, and 18 cycles per degree (cpd) spatial frequencies (participants’ mean age ± standard deviation: 37.3 ± 26.4 years). The CSV-1000 measurements were significantly higher for the 3 and 6 cpd spatial frequencies (both P = 0.01); however, at higher spatial frequencies, CS scores were similar. The highest and lowest differences between the two tests were recorded for the 3 cpd spatial frequency and 18 cpd spatial frequency, respectively. Except for the 3 cpd spatial frequency, in both eyes, the findings correlated significantly between the CSV-1000 and Metrovision (P < 0.05). The narrowest and widest limits of agreement between the two tests were found for the 12 and 3 cpd spatial frequencies, respectively. Conclusions: The CSV-1000 method estimated CS higher than the Metrovision method, mostly at lower spatial frequencies. Furthermore, the agreement between the two methods was greater at higher spatial frequencies than at lower frequencies. This should be kept in mind when using the two methods interchangeably in visual screening.

Evaluation of Building Vulnerability to Earthquake Using Rapid Visual Screening (RVS) Method

Indonesia is one of the countries prone to earthquakes. One of the earthquake disasters that occurred several years ago hit Palu and Donggala on September 28, 2018. It caused severe damage to infrastructure. Therefore, it is necessary to evaluate buildings vulnerable to earthquakes as a form of prevention. One of the buildings in Jember, the dr. Soebandi hospital, experienced cracks in the walls during an earthquake measuring 6.0 on the Richter scale in Nusa Dua Bali on July 16, 2019. This study carried out the risk assessment of the vulnerability of buildings to earthquakes using the Rapid Visual Screening (RVS) method from FEMA P-154. RVS is a method to identify a building that is potentially vulnerable to earthquake hazards based on visual observations from the exterior and interior of the building. The results of the evaluation using the RVS method showed that the dr. Soebandi hospital is categorized as safe and not prone to earthquakes, with a potential vulnerability percentage of 0.0126%. Based on these results, the building does not require special treatment to anticipate earthquakes; however, maintaining the occupants' safety and extending the building's life requires routine maintenance.

Assessment of Seismic Building Vulnerability Using Rapid Visual Screening Method through Web-Based Application for Malaysia

Rapid visual screening is a quick and simple approach often used by researchers to estimate the seismic vulnerability of buildings in an area. In this study, preliminary seismic vulnerability assessment of 500 buildings situated at Northern and Eastern George Town, Malaysia, was carried out by utilizing a modified FEMA-154 (2002) method that suits Malaysian conditions. Data were collected from online sources via Google Maps and Google Earth instead of traditional surveying data collection through street screening. The seismic assessment analysis of this study was based on the RVS performance score and the damage state classification for each building typology. This approach generates, for each building, a final performance score based on governing parameters such as structural resisting system, height, structural irregularities, building age, and soil type. The findings revealed the immediate need for effective seismic mitigation strategies, as 90% of the studied buildings required a further detailed analyses to pinpoint their exact seismic vulnerability performance. Most of the surveyed buildings were predicted to experience moderate-to-substantial damage, with 220 out of 500 being classed as damage state 2 (D2) and damage state 3 (D3). A GIS map, “RVS Malaysian Form-George Town Area”, was generated via ArcGIS and shared with the public to provide vital information for further research.

Penilaian Kerentanan Bangunan Terhadap Gempa Bumi pada Gedung Perkuliahan Berlantai Tinggi di Yogyakarta

Yogyakarta termasuk daerah yang memiliki tingkat resiko gempa yang tinggi, sehingga dapat mengakibatkan bangunan-bangunan yang didirikan di Yogyakarta memiliki potensi terhadap kerusakan. Gempa bumi yang terjadi pada tanggal 27 Mei 2006 masih meninggalkan trauma bagi masyarakat Yogyakarta, dimana menurut BNPB (2012) gempa di Yogyakarta menimbulkan korban jiwa sebanyak 4.674, dan sebanyak 19.897 dinyatakan cedera berat. Sebagian besar korban diakibatkan karena tertimpa bangunan, serta material rumah. Gempa di yogyakarta menimbulkan kerusakan yang berat pada bangunan sebanyak 96.790, sebanyak 117.075 alami kerusakan yang sedang, serta sebanyak 156. 971 bangunan alami kerusakan yang ringan. Pendirian bangunan-bangunan baru di wilayah Yogyakarta khususnya diharapkan dapat menerapkan prinsip bangunan tahan gempa pada tahapan-tahapan pembangunan agar tingkat kerentanan terhadap gempa tidak besar, salah satunya adalah proyek pembangunan gedung Research and Innovation Center of Dasron Hamid yang sedang dalam tahap pembangunan. Penelitian ini bertujuan untuk mengetahui tingkat kerentanan bangunan RIC terhadap gempa menggunakan RVS (Rapid Visual Screening) berdasarkan FEMA P-154 2015. Penelitian ini menggunakan metode kuantitatif dan observasi secara langsung di lokasi pembangunan dengan mengisi formulir FEMA P-154, bangunan yang ditinjau terdiri 8 lantai yang dilengkapi 1 lantai dasar. Formulir yang digunakan adalah tipe high seismicity yang berarti tingkat seismitas di lokasi penelitian memiliki persebaran gempa yang tinggi. Dari hasil penelitian didapatkan nilai S sebesar 2,3 dengan persentase kerentanan bangunan untuk roboh adalah 0,5%, sehingga aman terhadap gempa. Hal ini dikarenakan bangunan ini didirikan setelah adanya acuan atau code meskipun memiliki ketidakberaturan seperti vertical irregularity, dan, plan irregularity.