Mott MacDonald

About: Mott MacDonald is a company organization based out in London, United Kingdom. It is known for research contribution in the topics: Electric power system & Wind power. The organization has 586 authors who have published 529 publications receiving 9801 citations. The organization is also known as: Mott MacDonald Group & MMD.

Solutions for Foundation Systems Subjected to Earthquake Conditions

Abstract: Soil–structure interaction plays an important role in dynamic behaviour of a foundation under combined static and seismic loadings. This paper describes a few case histories with field studies of deeply embedded bridge foundations to showcase the earthquake induced lateral effects using finite element framework. Rigorous dynamic approach with detailed numerical analysis for large diameter pile foundation and pseudo-static approach for rigid caisson foundation presented in this study demonstrated the functionality of foundation systems in seismic conditions. Efficacy of barrettes over piles as a cost-effective foundation solution in high-rise buildings has also been discussed by obtaining higher resistance under static condition. Finally, an analytical methodology considering three-dimensional passive wedge developed in front of the rigid caissons is presented for estimating the ultimate soil resistance under seismic condition. Closed-form expressions to determine seismic passive earth pressure coefficient and its distribution along caisson length for different embedment ratio have been explained here that can be adopted in practice to analyse foundation systems subjected to earthquake condition.

Recommendation of RILEM TC 258-AAA: RILEM AAR-13: application of alkali-wrapping for concrete prism testing to assess the expansion potential of alkali-silica reaction

Abstract: The RILEM AAR-13 test procedure is not a test method by itself; rather it is a procedure applying alkali wrapping to concrete prisms during test exposure to assess the expansion potential of alkali-silica reaction. When combined with procedures of other test methods, for example AAR-10 or AAR-11, it becomes a full test procedure. The wrapping procedure described was originally proposed by a technical committee of the Japan Concrete Institute “Technical Committee on Performance Based Design and Maintenance Scenario with Controlling ASR Deterioration”. The procedure includes a detailed description of the materials to be used for wrapping, procedures for calculation of alkalinity of the solution that aims to simulate the pore solution of the concrete prism depending on the alkali content of the concrete, and finally specific procedures for storage and measurements of the prisms. The procedure of calculating the alkalinity of the solution to be applied for the wrapping is assumed to be conservative because no subtraction is made for assumed alkali binding by the hydrates or alkali absorption by the aggregates. The alkali content is estimated by adding the alkali contribution from all concrete constituents (except the aggregates) including the supplementary cementitious materials (SCMs).

Railway platform construction

Abstract: A prefabricated platform unit 1, for construction or refurbishment of a railway station platform, has a stepped upper surface 4b with a recessed planar forward portion 4a on which edge copers 23 are to be mounted. Refurbishment of an exiting platform may be performed by excavating a region 22 of the platform surface to the front edge, installing a prefabricated platform unit 1 in the excavated region, and installing edge copers 23. Construction of a new platform may include the steps of constructing foundations alongside the railway, constructing upstanding supporting members on the foundations, and mounting a superstructure including prefabricated platform units on the supporting members.