INVESTIGASI SUB-PERMUKAAN MENGGUNAKAN SURVAI PEMBIASAN SEISMIK‡
‡Technical note ini telah diterbitkan dalam Proceeding of 11th Symposium of Inter-University Forum for Transportation Studies (Forum Studi Transportasi Antar Perguruan Tinggi, FSTPT) at Semarang, Indonesia 2008.
Adi Purnomo, ST.¹; Sri Atmaja P. Rosyidi, Ph.D.²*; Anita Widianti, Ir., MT.³
¹Alumni Prodi Sarjana, Staf Pengajar (²Assistant Prof., ³Assoc.Prof.), Jurusan Teknik Sipil, Univ. Muhammadiyah Yogyakarta
*Korespondensi penulis, email: firstname.lastname@example.org
A seismic refraction survey is one of in situ non destructive testing (NDT) which is based on seismic waves. The method has been developed for the in situ measurement of sub-surface investigation on pavement design. The aim of this paper is to describe the use of the seismic refraction survey implemented on the geometric design of road pavement particularly for obtaining the soil bearing capacity of subgrade layer, profiling the soil stratification and identifying the soil type. In the seismic refraction method, the survey is divided into two parts, i.e. in situ data collection and analysis of intercept time graph. Data collection part performs the field measurement of seismic waves using the multi low-frequency geophones, seismograph and impact sources. The intercept graph is generated based on the first packing time of seismic waves recorded from field measurement. The graph is used to obtain the average Primary (P-) wave velocity of each layer of soil profile. Thus based on P-wave velocity and time arrival, the thickness of each layer and its soil type can be analyzed. Four common techniques used in seismic refraction data analysis, i.e. intercept time, delay time, critical distance and Generalized Reciprocal Method (GRM) technique were employed in this study. Then, the results obtained from these techniques were compared each other. From the results, it can be shown that those techniques are able to be used for soil investigation on subgrade layer for road pavement design.
Keywords: seismic refraction survey, P wave, road pavement design, NDT method
The complete article can be accessed in here: Seismik Refraksi_Adi et al; or copy this link: http://atmaja.staff.umy.ac.id/files/2010/11/Seismik-Refraksi_Adi-et-al.pdf, and paste into your browser.