DETERMINATION OF ENERGY ABSORPTION CAPABILITIES OF LARGE SCALE SHOTCRETE PANELS

The Western Australian School of Mines (WASM) has developed a facility for the static testing of full scale ground support elements. The test facility consists of several stiff steel frames used to support the sample and a screw feed jack is used to load the sample. A large scale punch test method has been developed to evaluate various shotcrete mix designs at different curing times. The shotcrete is sprayed on to a sandstone substrate containing an isolated disc that is centrally located. The test sample is placed on to the sample frame and restrained on all sides. The disc is displaced at a constant rate by the screw feed jack which in turn loads the sample. Instruments measure the displacement and the load being applied to the sample through the loading disc. The test method has been used to compare the force – displacement properties of different mix designs and reinforcing materials including plastic fibres, steel fibres and mesh. The force – displacement properties have been used to determine the energy absorbing capability of fibrecrete systems

NON-LINEAR, ELASTIC - PLASTIC RESPONSE OF STEEL FIBRE REINFORCED SHOTCRETE TO UNIAXIAL AND TRIAXIAL COMPRESSION TESTING

Understanding the complete stress-strain behavior of shotcrete is extremely important in ground support design; especially in cases where large deformations are expected such as around mine excavations at great depth. The application of non-linear numerical modeling to mining industry problems has increased in recent years. More realistic stress-strain response and failure criteria in complex plasticity models are also being used in the design of the larger, deeper mines. One of the factors to improve the reliability of numerical modeling is to properly define geotechnical parameters for both the rock mass and shotcrete surface support. Uniaxial and triaxial compression tests on steel fibre reinforced shotcrete (SFRS) have been used to quantify elastic-plastic response behaviour for both the peak and post-peak regions. The laboratory tests were conducted with a servo-controlled testing machine to obtain complete stress-strain curves. The test results include unconfined and triaxial compressive strength, shear strength and tensile strength together with the elastic and plastic mechanical properties of SFRS. A method is also suggested for obtaining the plasticity parameters for non-linear modeling of SFRS

Safety of switching from intravenous to subcutaneous rituximab during first-line treatment of patients with non-Hodgkin lymphoma: the Spanish population of the MabRella study

Rituximab is a standard treatment for non-Hodgkin diffuse large B-cell (DLBCL) and follicular (FL) lymphomas. A subcutaneous formulation was developed to improve the resource use of intravenous rituximab, with comparable efficacy and safety profiles except for increased administration-related reactions (ARRs). MabRella was a phase IIIb trial to assess the safety of switching from intravenous to subcutaneous administration of rituximab during first-line induction/maintenance for DLBCL or FL, focusing on ARRs. Efficacy, satisfaction and quality of life were also assessed. Patients received subcutaneous rituximab plus standard induction chemotherapy for DLBCL or FL for 4–7 cycles, and/or every 2 months maintenance monotherapy for FL for 6–12 cycles. The study included 140 patients: DLBCL, n = 29; FL, n = 111. Ninety-five percent of patients experienced adverse events, reaching grade ≥3 in 38 6% and were serious in 30 0%. AARs occurred in 48 6%, mostly (84 9%) at the injection site, with only 2 1% of patients reaching grade 3. The end-of-induction complete/unconfirmed complete response rate was 69 6%. After a median follow-up of 33 5 months, median disease-/event-/progression-free and overall survivals were not attained. The Rituximab Administration Satisfaction Questionnaire showed improvements in overall satisfaction and the EuroQoL-5D a good quality-of-life perception at induction/maintenance end. Therefore, switching to subcutaneous rituximab showed no new safety issues and maintained efficacy with improved satisfaction and quality of life

Spatial modeling of discontinuity intensity - Challenges and considerations

It is generally understood that discontinuity intensity can control a number of rock mass characteristics, such as rock mass strength and rock mass modulus, and influence rock mass response and behavior. Three-dimensional modeling can provide useful insights into the spatial variability of rock properties, however, there still are a number of aspects that hinders its full and comprehensive inclusion into rock mechanics applications. In contrast to traditional spatial modeling, where parameters are typified by scalar values (e.g. grade, density, etc.), one-dimensional discontinuity linear intensity parameters are vector variables and are unique to the borehole's orientation. The validity of spatial modeling of one-dimensional discontinuity linear intensity is therefore dependent on both the sampling direction and the degree of rock mass anisotropy. This paper describes some of the difficulties and considerations in the spatial modeling of discontinuity intensity from one-dimensional data. The paper also presents a three-dimensional test method to spatially quantify the degree of rock mass anisotropy. The method also allows practitioners to identify regions of the rock mass that have been isotropically sampled by drilling and where the spatial modeling of discontinuity intensity may be confidently applied. Copyright 2013 ARMA, American Rock Mechanics Association