scholarly journals Aplikasi Metode Geolistrik dan Analisis X-Ray Diffraction (XRD) untuk Investigasi Longsor di Pidada, Kecamatan Panjang, Bandar Lampung

EKSPLORIUM ◽  
2021 ◽  
Vol 42 (2) ◽  
pp. 131
Author(s):  
Rahmi Mulyasari ◽  
Suharno Suharno ◽  
Nandi Haerudin ◽  
Hesti Hesti ◽  
Ida Bagus Suananda Yogi ◽  
...  

ABSTRAK. Bandar Lampung merupakan wilayah perkotaan padat penduduk yang terdiri atas daratan dan perairan dengan beberapa dataran tinggi dan pegunungan yang terbentang di wilayah ini. Untuk mendukung pembangunan yang berkelanjutan di sebuah kawasan kota diperlukan konsep penataan wilayah yang mempertimbangkan segala aspek, salah satunya adalah aspek potensi bencana. Salah satu bencana yang berpotensi terjadi di Bandar Lampung, khususnya di Kecamatan Panjang, adalah gerakan massa/longsoran. Berdasarkan penelitian sebelumnya, daerah ini terekam memiliki beberapa titik sejarah longsor tetapi belum ada mitigasi/penanggulangan yang diaplikasikan khusus untuk jenis bencana tersebut. Tujuan dari penelitian ini adalah untuk mengetahui susunan batuan yang berada pada zona rawan longsor Kecamatan Panjang menggunakan metode geolistrik resistivitas serta untuk mengetahui hasil penilaian keteknikan tanah yang diperoleh dari hasil analisis litologi menggunakan X-Ray Diffraction (XRD). Hasil analisis dua lintasan geolistrik mengindikasikan adanya tiga lapisan litologi pada daerah penelitian, yaitu sedimen tuf dengan nilai resistivitas dan kedalaman antara (1–40 Ωm; 0,4–4 m), zona kontak atau bidang gelincir (40–120 Ωm; 2–4 m), dan breksi padu dengan komponen batuan beku (> 120 Ωm; 2–22 m). Selanjutnya berdasarkan hasil analisis penilaian keteknikan tanah, sedimen tuf sebagai lapisan permukaan yang mengalami longsoran diidentifikasi memiliki sifat keteknikan litologi yang rentan karena telah mengalami oksidasi dan pelapukan yang cukup intensif. Data yang diperoleh ini diharapkan dapat dimanfaatkan sebagai data dukung penataan wilayah berbasis potensi bencana.ABSTRACT. Bandar Lampung is a densely populated urban area consisting of land and water with several plateaus and mountains that stretch across this region. To support sustainable development in a city area, it is necessary to have a regional arrangement concept that considers all aspects, one of which is the potential disaster aspect. One of the potential disasters in Bandar Lampung, especially in Panjang District is a mass movement/landslide. Based on previous research, this area has been recorded as having several historical points of landslides, but there is no mitigation/response specifically for this type of disaster. The purpose of this study was to determine the arrangement of rocks that are in the landslide-prone zone in Panjang District using the geoelectric resistivity method and to analyze the soil engineering assessment obtained from the results of lithological analysis using X-Ray Diffraction (XRD). The results of the geoelectric analysis indicate that there are three lithological layers in the study area; namely tuff sediments with resistivity values and depths between (1–40 Ωm; 0.4–4 m), clay sand (40–120 Ωm; 2–4 m), and solid breccias with igneous rock components (>120 Ωm; 2–22 m). Furthermore, based on the results of the analysis of soil engineering assessments, tuff sediment as a surface layer that has experienced landslides has been identified as having susceptible lithological engineering properties because it has undergone quite intensive oxidation and weathering. The data obtained is expected to be used as supporting data for disaster potential-based regional planning.

1982 ◽  
Vol 71 (2) ◽  
pp. 603-610 ◽  
Author(s):  
V. G. Kohn ◽  
M. V. Kovalchuk ◽  
E. M. Imamov ◽  
B. G. Zakharov ◽  
E. F. Lobanovioh

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 73
Author(s):  
Juying Li ◽  
Qingsong Mei ◽  
Yana Li ◽  
Beihai Wang

Pure copper was subjected to high-pressure surface rolling (HPSR) to obtain a surface gradient layer. Effects of HPSR parameters on the surface microstructure and microhardness of Cu were investigated by using optical microscopy, transmission electronic microscopy, X-ray diffraction, and the microhardness test. The HPSR surface layer has a gradient microstructure consisting of increasingly refined grains with decreasing depth from the treated surface (DFS). The thicknesses of the refined surface layer can be up to ~1.8 mm, and the grain size of the topmost surface is down to ~88 nm, depending on the HPSR parameters including pressure, time, and temperature. Microhardness of HPSR samples increases with decreasing DFS, with a maximum of ~2.4 times that of the undeformed matrix. The present results indicated that HPSR could be an effective method for the production of a mm-thick surface layer on Cu with gradient microstructure and property.


1995 ◽  
Vol 39 ◽  
pp. 331-338
Author(s):  
Yoshihisa Sakaida ◽  
Keisuke Tanaka ◽  
Shintaro Harada

A new method of X-ray stress measurement was proposed to estimate non-destructively the steep residual stress distribution in the surface layer of ground Si3N4. We assumed an exponential decrement of the residual stress near the ground surface, and derived a formula for the lattice strain as a function of sin2Ψ. In the experiments, the diffraction angles were measured on the ground surface for a widest possible range of sin2ѱ using an Ω-goniometer. In order to measure the diffraction angle at very high sin η values, a scintillation counter was located on the -η side and an incident X-ray beam impinged on the ground surface with a very low angle from the +η side using the glancing incidence X-ray diffraction technique. A strong non-linearity was found in the 20-sin2ѱ diagrams especially at very high ѱ -angles. From the analysis of non-linearity, the stress distribution in the surface layer was determined. Tine residual stress took the maximum compression of 2 GPa at a depth of about 0.5 μm from the surface, and then diminished to zero at about 25 μm in depth. In the close vicinity of the ground surface, the compressive residual stress was relieved because of both the surface roughness and microcracking induced during the grinding process.


2016 ◽  
Vol 368 ◽  
pp. 99-102
Author(s):  
Lukáš Zuzánek ◽  
Ondřej Řidký ◽  
Nikolaj Ganev ◽  
Kamil Kolařík

The basic principle of the X-ray diffraction analysis is based on the determination of components of residual stresses. They are determined on the basis of the change in the distance between atomic planes. The method is limited by a relatively small depth in which the X-ray beam penetrates into the analysed materials. For determination of residual stresses in the surface layer the X-ray diffraction and electrolytic polishing has to be combined. The article is deals with the determination of residual stress and real material structure of a laser-welded steel sample with an oxide surface layer. This surface layer is created during the rolling and it prevents the material from its corrosion. Before the X-ray diffraction analysis can be performed, this surface layer has to be removed. This surface layer cannot be removed with the help of electrolytic polishing and, therefore, it has to be removed mechanically. This mechanical procedure creates “technological” residual stress in the surface layer. This additional residual stress is removed by the electrolytic polishing in the depth between 20 and 80 μm. Finally, the real structure and residual stresses can be determined by using the X-ray diffraction techniques.


2005 ◽  
Vol 40 (2) ◽  
pp. 199-209 ◽  
Author(s):  
V Fontanari ◽  
F Frendo ◽  
Th Bortolamedi ◽  
P Scardi

The incremental blind hole-drilling and the X-ray diffraction methods were used to measure the residual stress field introduced by shot peening in aluminium alloy 6082-T5 plates. Two peening treatments were selected to produce different depth extensions and peak values arising from different extents of plastic deformation in the surface layer. The results are discussed considering the various sources of uncertainty; in addition to the measuring technique, the effects of the surface treatment that usually induces a strong plastic deformation in the surface layer resulting in material work hardening and worsening of the surface morphology were considered. The residual stress profiles determined by the two methods showed quite good agreement for the two conditions, as regards the values both of the compressive peak and of the penetration depth. The present results provide mutual confirmation of the effectiveness of the two methods for the study of this class of materials.


1981 ◽  
Vol 212 (1188) ◽  
pp. 299-304 ◽  

X-ray diffraction has been used to measure the preferred orientation of the collagen fibrils, and their angular distribution within the tissue, as a function of depth from the articular surface in patellar cartilage. Measurements have been made at four different sites chosen to represent differing surface curvatures and régimes of wear. The orientation of fibrils in the surface layer allows it to oppose the swelling pressure exerted by the gel of hydrated glycosaminoglycans within the cartilage. An intermediate layer (where a bimodal distribution of fibrils is sometimes resolved) allows the orientation of the fibrils to change, with increasing depth, until they are roughly perpendicular to the articular surface. In this deep layer the fibrils can tie into the underlying calcified tissue so as to firmly anchor the cartilage. In the plane of the surface the fibrils tend to be aligned in the direction of stress caused by motion.


2013 ◽  
Vol 690-693 ◽  
pp. 2120-2125 ◽  
Author(s):  
Li Wen Tang ◽  
Jian Sun ◽  
Jin Zhang ◽  
Xin Bing Ou ◽  
Zhi Ming Zhou

As relatively new structure materials, magnesium and its alloys demonstrated significant potential for applications in many industries. However, magnesium alloys were easy to be corroded which greatly limited their development. AZ31B and AZ91D, two widely used commercial magnesium alloys in various industries, were chosen to be produced nanostructure on the surface layer, called Surface Nanocrystallization (SNC) by High Energy Spot Peening (HESP). The microstructure was characterized by Scan Electronic Microscopy (SEM) and X-ray diffraction (XRD) in this paper. Microhardness and corrosion resistance were measured by microhardness tester and electrochemical measurement system respectively. Experimental results showed that after HESP the grain sizes in the surface layer were obviously reduced into nanoscale; microhardness was greatly increased in the treated surface, about two times as much as that of original and corrosion current density in polarization curve was evidently raised while corrosion potential changed little.


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