KORELASI KERUSAKAN BATUAN PENYUSUN CANDI TERHADAP STABILITAS BANGUNAN BERDASARKAN SIFAT FISIS DAN MEKANIS
IRAWATI BUDI RESPATI, Dr.Ir. Ahmad Rifa'i, M.T
2014 | Tesis | S2 Teknik SipilCandi Prambanan merupakan benda cagar budaya dan termasuk dalam daftar warisan dunia, sehingga perlu dilestarikan keberadaanya. Secara geologis Candi ini berada di atas patahan aktif. Terjadinya gempa sebesar 5,9SR menyebabkan kerusakan-kerusakan pada Komplek Candi Prambanan. Kerusakan itu berupa kerusakan struktur maupun materialnya, dengan jenis dan kondisi kerusakan yang bervariasi. Penelitian ini lebih difokuskan pada batuan penyusun pada Candi Siwa yang merupakan candi utama pada Komplek Candi Prambanan. Tujuannya untuk mengetahui korelasi kerusakan batuan penyusun candi terhadap stabilitas bangunan berdasarkan sifat teknis dan mekanisnya. Dalam penelitian ini, untuk mengetahui karakteristik batuannya dilakukan pengujian di laboratorium maupun di lapangan, berupa uniaxial test, brazilian test, index properties, permeabilitas, uji kuat geser dan Schmidt Hammer Test tipe L. Selain pengujian terhadap batuan penyusun, analisis kestabilan struktur Candi Siwa didasarkan pada metode elemen hingga menggunakan software Plaxis v8.6. Tanah dan struktur candi dimodelkan 2D axysimmentry dan model mohr-coulomb, dimana material mengalami keruntuhan. Struktur candi ditinjau dalam tiga kondisi yaitu kondisi candi utuh (belum mengalami retakan), kondisi candi dengan retakan tanpa pengaruh interface dan kondisi candi retakan dengan pengaruh interface. Beban merata 5 kN/m2 dan 50 kN/m2 di halaman candi dan variasi gempa disimulasikan untuk mengetahui kestabilan struktur candi. Hasil korelasi nilai Schmidt Hammer dan UCS didapatkan persamaan UCS = 0,027Rn2 + 0,662Rn – 3,558 dengan koefisien korelasi (R²) = 0,903; dimana nilai Rn yang digunakan minimal 10. Dari grafik korelasi tersebut dapat dikatakan bahwa nilai UCS terbesar pada batu andesit merah, nilai UCS batu andesit hitam ½ dari nilai UCS batu andesit merah dan pada batu tuff nilainya 1 􀵗3 dari nilai UCS batu andesit merah. Simulasi pendekatan 2D dilakukan pada tiga kondisi struktur candi dengan diberikan beban merata di halaman dan variasi beban gempa. Adanya retakan dan interface mempengaruhi kestabilan struktur candi. Struktur Candi Siwa masih mampu menerima beban gempa dengan kondisi adanya retakan akibat gempa 2006, dimana ditunjukkan dengan peningkatan displacement yang tidak terlalu signifikan dan penurunan tegangan geser yang terjadi
Prambanan temple is a cultural sanctuary and included into a list world heritages, so the existence is necessary to preserve. Geologically, the temple is on the active fault. The 5,9 SR earthquake caused severe damages on the complex of Prambanan temple. The damages are both in structure and materials with various types and conditions of damage. This study is focused on the composing stones of Shiva temple as a main temple in the complex of Prambanan temple. The objective of the study is to find out a correlation between damages of the composing stones and the stability of building based on the technical and mechanical properties. In the study, a testing was done in both laboratory and field using Uniaxial Test, Brazilian Test, Index Properties, Permeability Test, Shear Stress Test, and Schmidt Hammer Test type L to find out the characteristics of stones. In addition, analysis of stability in the structure of Siva temple was based on element method using Plaxis software version 8.6. Soil and structure of the temple was modeled using the 2D axysimmetry and mohr-coulomb, where the materials had collapse. The structure of the temple was viewed in three conditions, i.e. those of complete temple (no fracture), of fractured temple without the effect of interface and of fractured temple with the effect of interface. The load was spread evenly for 5 kN/m2 and 50 kN/m2 in the yard of the temple, and variation in earthquake was simulated to find out the stability of the temple’s structure. Result of the correlation with values of Schmidt Hammer and UCS shown the equation, i.e. UCS = 0.027Rn2 + 0.662Rn – 3.558 with a correlation coefficient (R2) of 0.903, where minimal values of Schmidt Hammer used 10. From the correlaction graphic, it can be said that the highest values of UCS was in red andesite stone, where the value of UCS for black andesite stone was ½ of the value of UCS for the red andesite stone, while that of tuff was 1 􀵗3 of the value of UCS for the red andesite stone. The simulation by using the 2D approach done in three conditions of the temple’s sctructure, where load was evenly given in the yard and variation in earthquake. The presence of fracture and interfaces effect the structural stability on the temple. Shiva temple structure is still able to receive earthquake load with load conditions due to the presence of fracture earthquake in 2006, which is indicate by the increase in displacement is not too significant and the decrease in shear stress accurs.
Kata Kunci : UCS, Schmidt Hammer, Interface, simulasi numeris
