Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке
The World Stress Map (WSM) compiles information of the contemporary crustal stress using a wide range of very different stress indicator which can be grouped into four categories: • Earthquake focal mechanisms • Well bore breakouts and drilling-induced fractures • In-situ stress measurements (overcoring, hydraulic fracturing, borehole slotter) • Young geologic data (from fault-slip analysis and volcanic vent alignments)
В работе определены критерии оценки работы экранирующих щелей через коэффициент их защитной способности, рекомендованы решения для снижения ширины зоны остаточных деформаций, установлены параметры оконтуривающих зарядов для создания экранирующей щели с повышенной защитной способностью и выбраны параметры взрывания в приконтурной зоне.
The Rock Quality Designation (RQD) index was introduced 20 years ago at a time when rock quality information was usually available only from geologists’ descriptions and the percent of core recovery. The RQD is a modified core recovery percentage in which unrecovered core, fragments and small pieces of rock, and altered rock are not counted so as to downgrade the quality designation of rock containing these features. Although originally developed for predicting tunneling conditions and support requirements, its application was extended to correlation with in situ rock mechanical properties and, in the 1970s, to forming a basic element of several classification systems. Its greatest value, however, remains as an exploratory tool where it serves as a red flag to identify low-RQD zones which deserve greater scrutiny and which may require additional borings or other exploratory work. Case history experience shows that the RQD red flag and subsequent investigations often have resulted in the deepening of foundation levels and the reorientation or complete relocation of proposed engineering structures, including dam foundations, tunnel portals, underground caverns, and power facilities. <...>
В представленном курсе лекций рассматриваются основные общие правила, базовые принципы и особенности механико-математического моделирования, построения гранично-краевых задач геомеханики. В качестве примеров рассматриваются задачи подземной геомеханики(механики горных пород и массивов).
Rock slope design requires detailed knowledge of the rock joint fabric, which is the most important parameter in bench-scale analysis. Rock-fabric data for open pit slope design may be difficult to obtain because mine planning often requires design slope angles years in advance of excavation and outcrop exposure. When rockfabric data cannot be obtained from surface mapping, one of the most cost-effective alternatives to obtain these data is oriented-core drilling.
In the present study a new classification method for the assessment of ease of excavation of rock masses is proposed, based on the Geological Strength Index and the point load strength of the intact rock. The data originate from excavation sites in Greece in sedimentary and metamorphic rock masses. A wide variety of rock structures were considered, ranging from blocky to disintegrated, and different excavation methods have been used (blasting, hydraulic breaking, ripping and digging). The proposed method cannot be applied to heterogeneous rock masses and soft rocks/hard soils. <...>
