Deliverable 4.4 Risk Management

This deliverable 4.4 Risk Management is published under WP4 Control and real-time simulation of the construction of the ASHVIN project. 

Abstract

In order to develop comprehensive digital-twin supported site risk management regime it is important to collect data on productivity from well-documented previous construction activities. One of the highest risk activities in construction relates to unknown or unanticipated soil conditions. Soils are naturally occurring, variable materials whose properties depend on stress and strain level and vary temporally. Current design methods deal with uncertainty by assuming conservative estimates of soil properties and calculating the response of the geotechnical structure to some unlikely set of extreme loads. In certain analyses involving soil-structure interaction problems (e.g. soil retaining structures) the loads experienced by structural elements (such as piles, anchors, walls etc.) are directly related to the displacements (strains) experienced. Therefore, only a model that uses the most-likely soil and structure properties at any given point in the life-cycle of a structure to accurately predict the displacement can allow the real safety level (resistance to additional loading) of a structure to be determined.
This deliverable uses monitoring data collected from the construction of a deep sea quay wall to determine the real safety level of the wall throughout the construction programme. An advanced finite element model is implemented that can capture the real response. By comparing the measured and predicted response of the wall, a number of updates are initiated that incorporate the knowledge gathered and allow for reduction of uncertainty in a logical and consistent manner. The development of Ports is driven by ever increasing vessel sizes. To replace an existing quay wall to allow for larger vessels means an investment of several 100 million euros and a significant environmental cost in terms of CO2 emissions from new construction. In this report the digital twin developed demonstrated the safety level of the existing wall to several metres of additional dredging.