High-speed rail earthworks design developments and innovative trials – building Britain’s technical legacy

‍

Abstract

Selection of appropriate engineering mitigations for Britain’s new high speed rail line HS2 earthworks to ensure compliance with track slab performance criteria reflective of the railway’s high operating speed represents a major technical challenge which is exacerbated by the challenging ground conditions encountered in the central section (Contract C23) of Phase One. High plasticity over-consolidated clays and extremely weak and weathered mudstones are prone to large magnitude and long duration movements due to loading or unloading while weak deposits at shallow depths present risks for the subgrade’s static and dynamic performance (Rayleigh waves). To overcome the technical challenges associated with uncertainty in predicting long-term ground behaviour and ensuring subgrade performance with limited previous case studies on ground formations that had not been extensively studied, the C23 team developed and implemented collaboratively with the Client a number of large-scale innovative Cutting and Embankment trials to increase confidence in heave and settlement predictions, pursue significant design efficiencies, validate the geotechnical performance of engineering fill materials and maximise the material re-use of the site won soils. This lecture will share the new design developments and the lessons learnt from the successful earthworks’ trials describing how the C23 teams set new standards of practice for the industry while building a strong technical legacy which will be passed on to future infrastructure projects.

‍

Short Curriculum

Maria Dimitriadi is the Geotechnical Lead for EKFB and is currently responsible for the geotechnical delivery route wide for a large number of primary and secondary assets including earthworks, viaducts, overbridges, tunnels and highway diversions leading a team of more than 20 office and site-based staff. During her career, she has been involved in all aspects of geotechnical engineering from desk studies to detailed design and construction supervision as well as project managing several projects. Maria has previously presented on sustainable geotechnics and specifically on her research for the use of recycling materials for the stabilisation of expansive soils.

Maria has a BEng in Civil Engineering from University of Salford and an MSc in Soil Mechanics and Engineering Seismology from Imperial College London. She is a Chartered Member of the Institution of Civil Engineers (CEng MICE) and she is on the Register of Ground Engineering Professionals (RoGEP Professional).

‍

‍