Application of discrete fracture networks (DFN) in the stability analysis of Delabole Slate Quarry, Cornwall, UK

This is the author accepted manuscript. The final version is available from ARMA.50th US Rock Mechanics/Geomechanics Symposium, Houston, USA, 26-29 June 2016The failure mechanism of rock slopes is mainly controlled by the strength and orientation of discontinuities within the rock mass. A realistic representation of the joint network within the rock mass is therefore an essential component of stability analysis of rock structures (e.g. rock slopes, tunnels etc.). Discontinuity persistence and connectivity are significant parameters which control the stability of rock slopes. A small percentage of rock bridges on the discontinuity surface can significantly increase its strength and prevent slope failure. Discontinuities within the rock mass are rarely fully connected. In practice, however, discontinuities are often assumed fully persistent due to the difficulties both in mapping and simulation of non-persistence. Discrete fracture networks (DFN) provide a rigorous and convenient tool for the simulation of joint systems within a rock mass. Utilizing statistical methods, DFNs consider the stochastic nature of some key parameters (e.g. persistence and orientation) within numerical models. Discrete fracture network engineering is increasingly used due to recent developments in discontinuity data acquisition techniques (e.g. ground-based digital photogrammetry and laser scanning). Recent development in geomechanical modelling codes and increased computing power have also allowed to either import DFN’s into models or to generate DFN’s within the numerical modelling code itself (e.g. 3DEC). This paper describes the use of photogrammetry at the Delabole slate quarry in Cornwall, UK for remotely acquiring key discontinuity parameter data (orientation, intensity and length) and its subsequent use in developing statistically validated discrete fracture network parameters. The 3D distinct element code, 3DEC, is used for the DFN generation and subsequent stability analysis. Several realizations of the 3DEC-DFN models are run to investigate the stochastic nature of discontinuities within the quarry and their potential influence on the stability of the pit. Finally the simulation results are used to determine the slope instability mechanisms and determine the most likely areas of potential instability

BOSS Great Wall: morphology, luminosity, and mass

We study the morphology, luminosity and mass of the superclusters from the BOSS Great Wall (BGW), a recently discovered very rich supercluster complex at the redshift $z = 0.47$. We have employed the Minkowski functionals to quantify supercluster morphology. We calculate supercluster luminosities and masses using two methods. Firstly, we used data about the luminosities and stellar masses of high stellar mass galaxies with $\log(M_*/h^{-1}M_\odot) \geq 11.3$. Secondly, we applied a scaling relation that combines morphological and physical parameters of superclusters to obtain supercluster luminosities, and obtained supercluster masses using the mass-to-light ratios found for local rich superclusters. We find that the BGW superclusters are very elongated systems, with shape parameter values of less than $0.2$. This value is lower than that found for the most elongated local superclusters. The values of the fourth Minkowski functional $V_3$ for the richer BGW superclusters ($V_3 = 7$ and $10$) show that they have a complicated and rich inner structure. We identify two Planck SZ clusters in the BGW superclusters, one in the richest BGW supercluster, and another in one of the poor BGW superclusters. The luminosities of the BGW superclusters are in the range of $1 - 8\times~10^{13}h^{-2}L_\odot$, and masses in the range of $0.4 - 2.1\times~10^{16}h^{-1}M_\odot$. Supercluster luminosities and masses obtained with two methods agree well. We conclude that the BGW is a complex of massive, luminous and large superclusters with very elongated shape. The search and detailed study, including the morphology analysis of the richest superclusters and their complexes from observations and simulations can help us to understand formation and evolution of the cosmic web.Comment: Comments: 10 pages, 2 figures, A&A, in pres

Dipteren von den Kleinen Sunda-Inseln. Aus der Ausbeute der Sunda-Expedition Rensch. V. Bibionidae.

Nomenklatorische Handlungenhennigi Hardy, 1952 (Bibio), spec. n.furva Hardy, 1952 (Plecia), spec. n.sundaensis Hardy, 1952 (Plecia), spec. n.Nomenclatural Actshennigi Hardy, 1952 (Bibio), spec. n.furva Hardy, 1952 (Plecia), spec. n.sundaensis Hardy, 1952 (Plecia), spec. n

Studies of fruitflies associated with mistletoe in Australia and Pakistan with notes and decriptions on genera related to Perilampsis Bezzi (Diptera: Tephritidae).

Die bekannten mit Misteln (Loranthaceae) verbundenen Fruchtfliegenarten Asiens und des Pazifik werden behandelt und Bemerkungen zu verwandten afrikanischen Gattungen gegeben. Folgende Neubeschreibungen werden vorgenommen: Paraceratitella gen. n., P. eurycephala sp. n., P. oblonga sp. n., Ceratitella asiatica sp. n., C. bifasciata sp. n. und C, unifasciata sp. n. Trirhithromyia Hendel ist eine neue Kombination für Ceratitis (Trirhithromyia).Nomenklatorische Handlungenasiatica Hardy, 1967 (Ceratitella), spec. n.bifasciata Hardy, 1967 (Ceratitella), spec. n.unifasciata Hardy, 1967 (Ceratitella), spec. n.eurycephala Hardy, 1967 (Paraceratitella), spec. n.oblonga Hardy, 1967 (Paraceratitella), spec. n.Paraceratitella Hardy, 1967 (Tephritidae), gen. n.Trirhithromyia (Hendel, 1931) (Tephritidae), stat. n. hitherto subgenus of CeratitisThis paper treats the known species of fruitflies associated with mistletoe (Loranthaceae) in Asia and the Pacific and gives descriptive notes on related African genera. The following are described as new: Paraceratitella gen. n.? P. eurycephala sp. n., P. oblonga sp. n., Ceratitella asiatica sp. n., C. bifasciata sp. n., and C. unifasciata sp. n. Trirhithromyia Hendel is a new combination for Ceratitis (Trirhithromyia).Nomenclatural Actsasiatica Hardy, 1967 (Ceratitella), spec. n.bifasciata Hardy, 1967 (Ceratitella), spec. n.unifasciata Hardy, 1967 (Ceratitella), spec. n.eurycephala Hardy, 1967 (Paraceratitella), spec. n.oblonga Hardy, 1967 (Paraceratitella), spec. n.Paraceratitella Hardy, 1967 (Tephritidae), gen. n.Trirhithromyia (Hendel, 1931) (Tephritidae), stat. n. hitherto subgenus of Ceratiti