TEGANGAN DAN REGANGAN DINAMIS PERKERASAN SEMI FLEKSIBEL DENGAN MODIFIKASI REOLOGI ASPAL DAN SUBSTITUSI ZIOLIT PADA SEMEN MORTAR

Abstrak Ketahanan struktur perkerasan akibat timbulnya tegangan dan regangan menyebabkan retak awal saat terjadinya deformasi permanent sehingga kegagalan perkerasan akibat kelelahan umur tidak dihindarkan. Fenomena tersebut dapat dikurangi dengan perkerasan yang memiliki cukup kekakuan, kelenturan. Modifikasi material dilakukan untuk meningkatkan nilai kekakuan dan kelenturan campuran dengan menggunakan jenis campuran,gradasi, dan modifikasi aspal yang tepat sebagai usaha pengembangan campuran perkerasan beraspal. Tujuan dari penelitian ini  mempelajari tegangan dan regangan tarik campuran PSF  terhadap beban berulang dengan tambahan WTR dan menggunakan ziolit alam sebagai pengganti sebagian semen untuk mortar yang dinjeksi ke dalam rongga aspal porous. Desain campuran aspal berpori dimulai dengan penentuan proporsi aspal optimal dengan agregat bergradasi terbuka sebagaimana ditentukan dalam sepesifikasi (AAPA) 2004. Uji Marshall dilakukan untuk mengetahui spesifikasi yang disyaratkan dan dilanjutkan dengan uji specimen yang telah diinjeksi mortar semen dengan pengujian lentur metode pembebanan empat titik untuk evaluasi tegangan dan regangan tarik. Nilai tegangan dan regangan dinamis dianalisis pada setiap variasi ziolit dalam mortar semen. Substitusi ziolit alam pada semen mortar dapat mempengaruhi tegangan dan regangan dinamis campuran PSF, di mana semakin besar komposisi ziolit dalam semen mortar nilai tegangan dan regangan yang dihasilkan semakin tinggi. Kata kunci: perkerasan semi-fleksibel, ziolit alam, reologi aspal, tegangan dan regangan, beban dinamis  Abstract The resistance of the pavement structure due to the consequence of stress and strain causes the initial reset when the occurrence of permanent deformation so that pavement failure due to age is avoided. This phenomenon can be reduced by a pavement that has sufficient stiffness and flexibility. Material modification is carried out to increase the value of the stiffness and flexibility of the mixture by using the right type of mixture, gradation, and asphalt modification as an effort to develop an asphalt pavement mixture. The purpose of this study was to study the stress and tensile strain of the semi-flexible pavement (SFP) mixture against repeated loads with the addition of rubber tire waste (WTR) and to use natural zeolite as a part of cement for mortar injected into the porous asphalt cavity. The design of a porous asphalt mixture begins with the determination of the optimal proportion of asphalt with an open grade aggregate specified in the Asphalt Pavement Association Australia (AAPA) 2004.Marshall test is carried out to see the required specifications and test specimens that have been injected with cement with a four-point loading bending method test for stress evaluation and tensile strain. The values of dynamic stress and strain were analyzed for each variation of ziolite in cement mortar. Substitution of natural ziolite in cement mortar can affect the dynamic stress and strain of the PSF mixture, where the greater the ziolite composition in cement mortar, the higher the resulting stress and strain. Keywords: Pavement semi-flexible, natural zeolite, asphalt rheology, dynamic stress and strain

Development of Nationwide Vs30 Map and Calibrated Conversion Table for Indonesia using Automated Topographical Classification

A nationwide Vs30 map for Indonesia was developed based on automated topographic classification from 90-m grid digital elevation data and their correlation with Vs30. Automated topographic classification has been proposed by Iwahashi and Pike (2007) and a procedure to convert topographic class into Vs30 maps has been developed by Imamura and Furuta (2015) based on Vs data from J-SHIS (Japan Seismic Hazard Information System). In order to be suitable for Indonesia, calibration work according to Imamura and Furuta's procedure should be conducted since the geotechnical conditions in Japan may not be the same as in Indonesia. This paper presents adjustment of the Vs30 correlation by Imamura and Furuta to convert topographic class into Vs30 and construct a Vs30 map of Indonesia. This correlation was calibrated by using Vs data from BMKG (Indonesian Agency for Meteorological, Climatological, and Geophysics) as well as standard penetration test logs that were collected by the authors. Utilization of local field measurement data will certainly enhance the reliability of the Vs30 map. The developed nationwide Vs30 map will be very useful for disaster mitigation programs and for preliminary design of earthquake resistant buildings and infrastructure in Indonesia

Stabilization On Expansive Soil For Road-Subgrade For Geotechnic Disaster Approach

This research was conducted for Blang Dalam expansive clay is located in Pidie Jaya-Aceh, Sumatra-Indonesia, which is one of the embankment material used as road subgrade. Road construction use expansive clay soil for subgrade experiencing many damages. The damage of road construction is caused by low bearing capacity when water levels change, high soil plasticity results swelling experience and shrinkage during the rainy and dry season respectively. One method of expansive clay stabilization effort to increase the carrying capacity of the soil is a mixture of Lime Ca (OH)2. Lime mix percentage variation are; 3%, 6%, 9% and 12% of the dry weight of soil. The purpose of this research is to determine the effect of lime a stabilizing agent to the improvement of the physical and mechanical properties of expansive soil. The result of untreated soil for free swelling is 1.141 % and swelling pressure of 23.18 kPa. For treated soil-lime mixture of 3%, 6%, 9% and 12%, the free swelling value are 0.64 %, 0.47 %, 0.40 % and 0.23 % respectively. Moreover, swelling pressure values for lime variation of 3%, 6%, 9% and 12% are 15.44 kPa, 13.25 kPa, 10.51 kPa, and 9.79 kPa respectively. 12% of soil-lime results shows the most effective results of free swelling which decrease for 1.14% of untreated soil to 0.23% and swelling pressure value of 23.18 kPa for untreated soil decline to  9.79 kPa

Faktor Keamanan Stabilitas Lereng pada Kondisi Eksisting dan Setelah Diperkuat Dinding Penahan Tanah Tipe Counterfort dengan Program Plaxis

The Aceh Tengah / Gayo Lues-Blangkejeren road segment (N.022) Km 438 + 775 is one of the Central Cross National Roads in the Province of Aceh, which often experiences landslides due to being in hilly areas. Landslides that occur in these locations are caused by scouring of road runoff, lack of optimal drainage and the absence of outlets for drainage and soil layers under asphalt pavement consisting of loose material. Therefore, a slope reinforcement study with Counterfort type retaining wall is needed. This study aims to analyze slope stability by obtaining safety factor numbers and identifying slope failure patterns. Analysis was carried out to obtain safety factors and slope failure patterns by using 2D Plaxis and slice methods. The calculation of safety factors for Counterfort type retaining walls is done manually. The input soil parameters used are dry volume weight (gd), wet volume weight (gw), permeability (k), modulus young (Eref), paisson's ratio (υ), shear angle (f), cohesion (c) . The results of slope stability analysis on the existing conditions using the Plaxis program and the slice method with radius (r) 65.06 meters found that safety factors were 1.038 and 1.079 with unsafe slope conditions (FK 1.25). The results of the analysis after reinforced counterfort and minipile type retaining wall with a length of 12 meters found 1,268 safety factor numbers with unsafe slope conditions (FK 1,5). Thus, additional reinforcement is needed by using anchor on the counterfort. The results of slope stability analysis after reinforced counterfort, minipile and anchor type retaining walls with a length of 20 meters and a slope of 30 ° were obtained with a safety factor number of 1.513 with safe slope conditions (SF 1.5).ABSTRAKRuas jalan batas Aceh Tengah/Gayo Lues-Blangkejeren (N.022) Km 438+775 merupakan salah satu ruas jalan Nasional Lintas Tengah Provinsi Aceh, yang sering mengalami terjadi tanah longsor karena berada di daerah perbukitan. Longsoran yang terjadi pada lokasi tersebut disebabkan oleh gerusan air limpasan permukaan jalan, kurang optimalnya drainase dan tidak adanya outlet untuk pembuangan air serta lapisan tanah di bawah perkerasan aspal terdiri dari material lepas. Oleh karena itu, diperlukan kajian perkuatan lereng dengan dinding penahan tanah tipe Counterfort. Kajian ini bertujuan untuk menganalisis stabilitas lereng dengan mendapatkan angka faktor keamanan dan mengidentifikasi pola keruntuhan lereng. Analisis dilakukan untuk mendapatkan faktor keamanan dan pola keruntuhan lereng yaitu dengan menggunakan program Plaxis 2D dan metode irisan. Perhitungan faktor keamanan untuk dinding penahan tanah tipe Counterfort dilakukan secara manual. Adapun parameter  tanah input yang digunakan adalah berat volume kering (gd), berat volume basah (gw), permeabilitas (k), modulus young (Eref), paisson’s rasio (υ), sudut geser (f), kohesi (c). Hasil analisis stabilitas lereng pada kondisi eksisting menggunakan program Plaxis dan metode irisan dengan jari-jari (r) 65,06 meter didapatkan akan faktor keamanan sebesar 1,038 dan 1,079 dengan kondisi lereng tidak aman (FK 1,25). Hasil analisis setelah diperkuat dinding penahan tanah tipe counterfort dan minipile dengan panjang 12 meter didapatkan angka faktor keamanan 1,268 dengan kondisi lereng tidak aman (FK 1,5). Dengan demikian, maka diperlukan perkuatan tambahan dengan menggunakan angkur pada counterfort. Hasil analisis stabilitas lereng setelah diperkuat dinding penahan tanah tipe counterfort, minipile dan angkur dengan panjang 20 meter serta sudut kemiringan 30° didapatkan angka faktor keamanan 1,513 dengan kondisi lereng aman (SF 1,5).Kata kunci : longsoran; counterfort; plaxis 2D; faktor keamanan

KAJIAN POTENSIAL LIKUIFAKSI AKIBAT GEMPA BERDASARKAN DATA SPT-N DI WILAYAH PROVINSI ACEH

Provinsi Aceh merupakan wilayah yang rawan gempa. Gempa Aceh 26 Desember 2004 dan 7 Desember 2016 telah mengakibatkan terjadinya likuifaksi di beberapa tempat. Likuifaksi telah banyak menjadi penyebab dari kerusakan bangunan dan sarana infrastruktur. Sehingga perlu dikaji potensi likuifaksi di daerah pesisir yang banyak terdapat pemukiman penduduk, bangunan bertingkat dan infrastuktur. Kajian potensi likuifaksi menggunakan data N-SPT, dilakukan dengan menggunakan MetodeKishida (1969), Metode Whitman (1971), serta Metode Valera dan Donovan (1977). Magnitude gempa yang diterapkan adalah 6 SR, 8 SR dan 9 SR. Metode Kishida (1969) memberikan hasil bahwa untuk magnitude gempa 6 SR, 8 SR dan 9 SR tidak berpotensi likuifaksi pada lapisan 3m – 21m. (1971) pada magnitude gempa 6 SR tidak mengalami likuifaksi pada tiap lapisan tanah. Sedangkan Metode Valera dan Donovan (1977) semua lapisan tanah mengalami likuifaksi pada setiap magnitude gempa kecuali pada kedalaman 3m. Gabungan dari ketiga metode di atas memberikan hasil bahwa seluruh lapisan berpotensi likuifaksi kecuali pada lapisan 3 m dengan magnitude gempa 6 SR Dengan demikian pembangunan gedung dan infrastruktur di daerah Pesisir Utara Aceh Provinsi Aceh perlu didahului dengan usaha perbaikan tanah untuk mengantisipasi fenomena likuifaksi

Development of Nationwide Surface Spectral Acceleration Maps for Earthquake Resistant Design of Bridges Based on National Hazard Maps of Indonesia 2017

Spectral acceleration at the ground surface, including peak ground acceleration, provides essential information for earthquake resistant design and must be provided to bridge engineers in easily accessible media. Spectra acceleration maps are one way to deliver such information, but unfortunately the most recent Indonesian earthquake resistant design standard for bridges, SNI 2833-2016, only provides maps of earthquake hazard at bedrock. The development of earthquake acceleration maps at the ground surface for Indonesia in this study was based on earthquake hazard maps at bedrock with probability of exceedance (PE) 7% in 75 years, i.e. equal to an earthquake with a return period of 1034 years. Site conditions were adopted from the nationwide Vs30 map of Indonesia proposed by Irsyam (2017), which is a modified version of the Vs30 map proposed by Imamura & Furuta (2015). Site conditions combined with hazard value were used to determine the amplification factors according to the criteria in SNI 2833-2016 and then multiplied with hazard at bedrock to obtain surface spectra acceleration maps. The resulting maps are very useful for determining earthquake loads for bridge design at the preliminary design stage. Improvements to incorporate more advanced calculation methods and updated data in a future research are recommended and very feasible

Sumatra-fault earthquake source variation for analysis of liquefaction in Aceh, Northern Indonesia

Introduction: Areas that are situated on active faults experience a severe risk of earthquakes. During earthquake shocks, pore water pressure increases and soil shear strength decreases, resulting in water saturation of the loose sand layer and the possibility of liquefaction. Banda Aceh is a city on Sumatra Island, northern Indonesia, located on active faults that run along Sumatra Island. Aims: To ascertain the liquefaction potential in Banda Aceh City, it is important to conduct a research analysis on the soil profile below Banda Aceh City. This research focused on earthquake acceleration to determine the strength capacity of soil to withstand loads and wave propagation to minimize infrastructure failure. Methods: The liquefaction potential of Banda Aceh was determined by analyzing N-SPT records from three sites using three different approaches. This liquefaction study considered the cyclic loading and seismic acceleration associated with the Sumatra-fault earthquake source, which has a design magnitude of Mw 9.3. Results: The results of cyclic loading showed that Banda Aceh City has liquefaction potential. Using the 3D surface approach, soil profiling gives a crossvault-shaped soil profile that shows liquefaction potential starting at 2.5 m and the hard soil layer found at 6.0 to 10 m. Conclusion: This study examined the liquefaction potential of Banda Aceh City. The research was carried out using a simplified approach to determine the liquefaction potential index (LPI) at three-dimensional cross faults of discontinuous sand generated by the Sumatra-fault acceleration of earthquak

KAJIAN STABILITAS COUNTERFORT WALL PADA ESCAPE HILL TERHADAP FREEBOARD DAN RUN UP LEVEL

Kota Banda Aceh termasuk salah satu daerah yang terkena bencana tsunami pada 26 Desember 2004 dengan kekuatan gempa 9,3 SR. Mengingat berbagai ancaman gempa yang menimbulkan tsunami dan masih kurangnya upaya yang optimal dalam pembangunan tempat evakuasi maka perlu dilakukan kajian-kajian terhadap tempat evakuasi sementara yaitu bukit buatan (escape hill). Salah satu cara penanggulangan konstruksi bangunan terhadap pengaruh freeboard dan run up level adalah penggunaan dinding tegak pada salah satu model tempat evakuasi tsunami. Tujuan dari penelitian ini adalah mengetahui nilai stabilitas dinding tegak pada escape hill dan faktor keamanan dari dinding tegak. Lokasi penelitian dilakukan di Desa Tibang, Kecamatan Syiah Kuala diperoleh tinggi run up maksimum pada saat tsunami 2004 mencapai 3,70 m. Data yang diperoleh dari lapangan kemudian dibawa ke laboratorium dan dianalisis dengan menggunakan program Plaxis. Kajian dinding penahan tanah pada tempat evakuasi sementara ini menggunakan dinding penahan tipe counterfort wall, stabilitas dinding diperoleh pada ketinggian 8 m. Dari pemodelan yang telah dilakukan, menunjukkan bahwa pemodelan material site dengan variasi nilai kohesi tanah c sebesar - 25% dan sudut geser dalam tanah φ sebesar + 5% dengan faktor keamanan 2,614 > 1, menghasilkan faktor keamanan yang paling tinggi dibandingkan dengan variasi yang lain. Nilai-nilai parameter tanah (material site) dengan variasi c - 25% sebesar 0,032kN/m2 dan φ + 5% sebesar 32,469º dapat diusulkan untuk menetapkan TOR (Term Of Reference) dan RKS (Rencana Kerja dan Syarat-syarat) dalam pelaksanaan pembangunan escape hill ini