Structural geological complications for tunnel construction in the Kostenets’s section of the Maritsa fault zone in Central Bulgaria

The structural geological features defining the discontinuity network in metamorphic rocks hosting railway tunnels are described. Discussion on the faults, joints, lineation and stresses found from fault population is presented. It is demonstrated that the formation of some brittle joints is related to the ductile stretching lineation. The geotechnical situation for the tunnel construction is complicated and requires reassessment of the design solutions in order to accommodate substantial lateral forces and prevent shear of the tubes.

In-Situ Block Characterization of Jointed Rock Exposures Based on a 3D Point Cloud Model

The importance of in-situ rock block characterization has been realized for decades in rock mechanics and engineering, yet how to reliably measure and characterize the geometrical properties of blocks in varied forms of exposures and patterns of jointing is still a challenging task. Using a point cloud model (PCM) of rock exposures generated from remote sensing techniques, we developed a consistent and comprehensive method for rock block characterization that is composed of two different procedures and a block indicator system. A semi-automatic procedure towards the robust extraction of in-situ rock blocks created by the deterministic discontinuity network on rock exposures (PCM-DDN) was developed. A 3D stochastic discrete fracture network (DFN) simulation (PCM-SDS) procedure was built based on the statistically valid representation of the discontinuity network geometry. A multi-dimensional block indicator system, i.e., the block size, shape, orientation, and spatial distribution pattern for systematic and objective block characterization, was then established. The developed method was applied to a synthetic model of cardboard boxes and three different rock engineering scenarios, including a road cut slope from Spain and two open-pit mining slopes from China. Compared with existing empirical methods, the proposed procedures and the block indicator system are dependable and practically feasible, which can help enhance our understanding of block geometry characteristics in related applications.

Computational framework for discontinuity network characterization

<p>The topological and geometrical description of fault and fracture networks is an essential first step in any investigation of fractured or faulted media. The spatial arrangement, density, connectivity, and geometry of the discontinuities strongly impact the physical properties of the media such as resilience and permeability. Obtaining reliable metrics for characterizing fault and fracture networks is of interest for mining engineering, reservoir characterization, groundwater management, and studies on the regional fluid flow history. During large-scale studies, we mostly rely on two-dimensional lineaments obtained through structural mapping, outcrop analysis, or remote sensing. An efficient and widely applicable framework for discontinuity network characterization should therefore be based on the analysis of the frequently available two-dimensional data sets.</p><p>Here, we present an automated framework for efficient and robust characterization of the geometric and topologic parameters of discontinuity networks. The geometry of the lineaments is characterised based on orientation, length, and sinuosity. The underlying distribution of these parameters are determined, and representative probability density functions are reported. The connection between the geometric parameters is validated, e.g. correlation between orientation and length. The spatial arrangement is determined by classical line- and window-sampling, by assessing the fractal dimension, and via graph-based topology analysis.</p><p>In addition to the statistical analysis of lineament networks, we show how the graph data structure can be utilized for further characterization by linking it to raster data such as magnetic, gravimetric, or elevation. This procedure not only yields an additional means for lineament characterization but also allows users to assess dominant pathways based, for instance, on hydraulic gradients. We demonstrate the applicability of our algorithm on synthetic data sets and real-world case studies on mapped fault and fracture networks.</p><p>We finally show how our framework can also be utilized to design detailed numerical studies on the fluid flow properties of analysed networks by conditioning mesh refinement on the type and number of intersections. In addition, due to known scaling relationships our framework can help to determine appropriate parameters for the simulations. We provide examples of statistically parametrized fluid flow simulations in natural discontinuity networks and show the impact of conceptualizing the lineaments as conduits, barriers or conduit-barrier systems.</p>

Deep geoelectrical investigation to bound a coastal thermal outflow area

The coastal carbonate Apulian aquifers, located in southern Italy, feed several coastal fresh springs and constitute the main local source of high quality water. The Santa Cesarea Terme cave system is almost unique case of hypogenic coastal spring caves, located along the Adriatic Sea coastline and hosting spring coastal outflow of mixed groundwater (from 22°C to 33°C) mainly of thermal groundwater due to infiltration offshore, in the sea bottom, and pure fresh groundwater due rainfall infiltration. Thermal springs and the outflow system are strictly controlled by both the discontinuity network and the karst processes involving the foreland environment. Detailed geoelectrical prospecting were carried out to bound the upflow continental area of this system, considering the geoelectrical effects of deep water mixing with different salinity and temperature close the Adriatic coast.

GAMBARAN LESI TRAUMATIK MUKOSA MULUT PADA LANSIA PENGGUNA GIGI TIRUAN SEBAGIAN LEPASAN DI PANTI WREDHA KABUPATEN MINAHASA

Removable partial dentures (RPDs) are artificial teeth that replaces one or more missing teeth in the upper jaw or lower jaw and can be removed by the patient. Elderly is an aging process that is experienced by everyone and can not be avoided by anyone. Traumatic lesions is a condition of discontinuity network extends from the dermis to the subcutaneous and always occurs in pathological conditions. His study aimed to describe traumatic oral mucosal lesions in elderly using removable partial dentures in nursing homes.This was a descriptive study with cross sectional approach. Social Institution used were Tresna Agape Tondano Elderly, Social Institution Ina I, Deborah Werdha Panti, Panti Yakobus Peduli Elderly, Elderly Nursing Hana, Tabitha Nursing Elderly and Elderly Nursing Pengasih. Samples were all elderly that used Most Removable Teeth. The results showed that the majority of elderly using removable teeth in Minahasa regency nursing homes have experienced traumatic lesions. Conclusion: Most of the elderly using removable partial dentures in Minahasa district nursing homes had experienced traumatic lesions caused by removable partial dentures.Keywords: removable partial dentures, elderly, traumatic lesions.Abstrak: Gigi tiruan sebagian lepasan (GTSL) adalah gigi tiruan yang menggantikan satu atau beberapa gigi yang hilang pada rahang atas atau rahang bawah dan dapat dilepas oleh pasien. Lesi traumatik merupakan kondisi diskontinuitas jaringan yang meluas dari dermis hingga ke subkutis dan selalu terjadi pada kondisi patologis. Tujuan Umum, untuk mengetahui gambaran lesi traumatik mukosa mulut pada lansia pengguna gigi tiruan sebagian lepasan di panti wredha.Tujuan Khusus, untuk mengetahui gambaran lesi traumatik mukosa mulut pada lansia pengguna gigi tiruan sebagian lepasan di Panti Wredha kabupaten Minahasa yang di tinjau dari lokasi lesi pada mukosa mulut. Jenis penelitian ini yaitu penelitian deskriptif dengan pendekatan cross sectional.Gambaran lesi ulseratif terhadap pengguna gigi tiruan sebagian lepasan pada lansia di panti werdha kabupaten minahasamenunjukkan sebagian besar pernah mengalami lesi ulseratif, dan yang terbanyak pada perempuan (93,3%). Lokasi yang paling sering terkena yaitu lidah (55,17%). Penyebab ulkus yang paling sering yaitu trauma bagian dasar/sayap GTSL (62,1%). Lesi ulseratif terjadi dengan frekuensi tidak teratur (68,9%). Responden paling banyak membiarkan ulkus tanpa pengobatan (48,3%), sedangkan 51,7% responden mengobati sendiri dimana 73,3% diantaranya menggunakan obat topikal. Simpulan: Sebagian besar lansia pengguna gigi tiruan sebagain lepasan di Panti Wredha kabupaten Minahasa telah mengalami lesi traumatik.Kata kunci: gigitiruan sebagian lepasan, lansia, lesi ulseratif

Fractal Description of Rock Mass Structure Representative Elementary Volume

The mechanical parameters of the rock masses are scale dependent because of the existence of the discontinuities. The self-similarity of the discontinuities makes the application of fractal theory in the description of the rock mass structure possible. The novel point in this study is that the structure representative elementary volume (SREV) of rock mass is proposed. Rock mass structures were obtained through the two-dimensional discontinuity network simulation results, from which ten pieces of square rock mass specimens were chosen. The side lengths of the specimens were increased in turn from 1m to 10m. And the fractal dimension of each specimen with different sizes was calculated by the box-counting principal of the fractal geometry. The fractal dimensions of the rack mass structures became larger with their side lengths increasing, and finally stable. And the SREV of the rock mass was determined based on the variation rule of the fractal dimensions. Further, the relation between the structure representative elementary volume (SREV) and mechanical parameter representative elementary volume (REV) was qualitatively analyzed from the strength differences between the discontinuities and intact rock. And the conclusion was inferred that the size of the SREV was the upper limit of mechanical parameter REV. Meanwhile, the conclusion was verified by the results of the finite element method. This study can provided a referring value for the estimation of the mechanical parameter REV in future.

3D ROCK MASS GEOMETRICAL MODELING WITH ARBITRARY DISCONTINUITIES

This paper describes an algorithm to generate the realistic numerical representation of three-dimensional rock masses. The discontinuities can be treated as infinite or finite planes with or without thickness. A finite plane is represented by a polygon and defined using centroid of the polygon, orientation, geometry in 2D plane, the angle between strike line and reference line and other properties including cohesion, friction angle, tensile strength and aperture. Through 3D discontinuity network simulation, the information of discontinuities is obtained as the input data for block generation. The block generation process includes boundary planes cutting, discontinuities cutting and block integration. The results are also verified by graphical check, topological and geometrical properties of a polyhedron. The algorithm we adopt is convenient to be developed into a computer program. The generated model, in which the blocks and loops of blocks could be convex or concave, can be used for single block stability analysis or block model codes like discrete element method (DEM) and discontinuous deformation analysis (DDA).