Presentation on theme: "INSIDE Innovations on Stability Improvements enabling Dyke Elevations Dr P.R. Smith A competition organised by:"— Presentation transcript:
INSIDE Innovations on Stability Improvements enabling Dyke Elevations Dr P.R. Smith A competition organised by:
The Problem Climate change leading to a rise of water level and hence need to raise dykes. Downstream reinforcement not desirable because of buildings. Upstream reinforcement not desirable because of the policy of ‘Space for the River’.
The Problem Help! Is there nobody with a better solution?
Reference Location: Opperduit on River Nederlek Situation circa 1850 Situation today
The Challenge: Macro-stability Loss of stability due to dyke raising and uplift during high water
The Challenge: Soil Profile Typical soil profile of West Holland: 12 m weak cohesive soil on top of Pleistocene sand
Selection Criteria Minimum safety-factor of 1.2. Feasibility (materials, life span 50 to 100 years). Quality control methods for Mix In Place (MIP). Compatible with surroundings. Control and maintenance (sustainability). Cost Research Method Statement.
... AND THE WINNER IS..... The consortium consists of: 2001 - Preliminary design 2002 - Final design (advanced modelling) - Validation phase (laboratory testing) 2003 - Practical phase (trial location, monitoring) 2004 - Evaluation phase (results published) If feasible: technique implemented in Dutch design codes The prize: Assessment of feasibility of MIP technique
Location of MIP in toe or dyke slope. Influence on displacements (resistance against shear forces). Anchored in Pleistocene sand. Control over horizontal water flow.
Alternative arrangements of MIP Columns 3-D view Top View Arching effect in MIP columns
Final Design: Advanced Modelling PLAXIS 2-D: interaction of soil with columns shear strength of columns inclination of columns location of columns displacements groundwater flow PLAXIS 3-D: arching in soil