Fault slip in a mining context

Recent articles on the broad range of computational and analytic techniques currently used to investigate excavation collapse are reported. Advances in physical models are also described. Simple models for determining fault slip due to underground and surface excavations and structures are investigated

Exact seismic response of smooth rigid retaining walls resting on stiff soil

The assessment of forces exerted on walls by the backfill is a recurrent problem in geotechnical engineering, owing to its relevance for both retaining systems and underground structures. In particular, the work by Arias and colleagues, and later also the one by Veletsos and Younan, among others, becomes pertinent when considering pressure increments on underground structures triggered by seismic events. As a first step, they studied the response of a rigid retaining wall resting on rigid bedrock subjected to SV waves, introducing some simplifying assumptions. This paper presents the exact solution to this reference problem. The solution is given in horizontal wavenumber domain; hence, it comes in terms of inverse Fourier transforms, which can be approximated numerically in Mathematica , which in turn are verified against finite‐element simulations. Specific features of this exact solution that were not captured by prior engineering approximations are highlighted and discussed

Concentration changes due to cathodic protection

By solving the appropriate diffusion equations the concentration changes are calculated in the environment of underground structures protected cathodically. It is shown that these changes are negligible under all practical circumstances

Technical and economic effect of the selection and operation of cathodic protection installations

Underground metallic structures are now an integral part of any industrial or commercial facility. The length and the number of such objects increases continuously. Are the new line of oil fields, gas pipelines, erection of storage of petroleum products, public utilities, information networks. It is obvious that stable operation of the industry, are used where underground metallic structures depends largely on their reliability. At the stages of design, construction and operation of underground metal structures, the problem arises to protect them from soil corrosion underground. It is known that to reduce the impact of soil (electrochemical) corrosion widely used method of bias potential on the protected construction in a negative region relative to the surrounding soil (soil) by applying external source of energy - the installation of cathodic protection

Drain System Around the Underground Cavern

In recent years, construction or planning of large-scale underground structures, such as underground power plants, underground oil storage plants and nuclear power plants have been coming into consideration in Japan. To construct such as large-scale underground structures, one of the most important problems is to make clear beforehand the behavior of groundwater around these structures and the other is to carry out proper countermeasure of groundwater, so that these structures can be constructed safely and maintained stability over a long time period. This report describes the results of theoretical studies on the drain systems and at the same time, discusses the drain systems around the underground cavern for the practical underground power stations

Influence of seismic events on shallow geotechnical structures

This paper deals with a summary of possible seismic loading of shallow geotechnical structures. It is known that seismic loading influences the underground structures much less than the structures on the surface, therefore, it is not usually taken into account. However, cracks or damage in lining occur due to vibration from time to time. Two effects of earthquakes are documented on these structures: an effect due to faulting and an effect due to vibration. At present, FEM is the most popular method to solve the above problems. Integrated earthquake simulation is the most frequent task that has a significant impact on seismic hazard and seismic risk estimations, and human actions against earthquake disasters. Three types of rock massif were defined for this study: soft rock, medium hard rock, and hard rock. More detailed description and sensitivity analysis are performed for circle cross-section of those structures. Sensitivity analysis was performed using soil interaction method according to Wang's methodology; change of lining diameter and elastic modulus of lining were tested. Thrust force must also be calculated for the no-slip condition. Graphs presented in this paper document individual relations between individual studied parameters. These results can be used as sufficient accurate final analysis while idealised conditions can be accepted.Web of Science22442141

International Benchmarking in Electricity Distribution: A Comparison of French and German Utilities

In this paper we present an international cross-country benchmarking analysis for utility regulation of France and Germany, the two largest electricity distribution countries in Europe. We examine the relative performance of 99 French and 77 German distribution companies operating within two different market structures. This paper applies several parametric benchmarking approaches to assess the relative technical efficiency of the utilities, such as deterministic Corrected Ordinary Least Squares (COLS) and Stochastic Frontier Analysis (SFA). Our base model uses the number of employees as a proxy for labor and network length as a proxy for capital as inputs. Units sold and the numbers of customers are considered as outputs. Our model variations and extensions analyze the effect of different characteristics of distribution areas (e.g. population density and the choice of investment in underground cable network). We find that utilities operating in urban areas feature higher efficiency scores and that investment in underground cables increase the technical efficiency of the distribution utilities.International benchmarking, electricity distribution, parametric efficiency analysis

The effects of LHC civil engineering on the SPS and LEP machines

The LHC will utilise much of the existing LEP infrastructure but will require many new surface buildings and several smaller underground structures, two new transfer tunnels from the SPS to the LHC an d two huge cavern complexes to house the ATLAS and CMS experiments. Excavation for the underground structures will start while LEP and SPS are running, causig the existing tunnels in close proximity t o move. The predicted movements are of sufficient amplitude to prevent machine oepration if no precautions are taken