Cavities and sinkholes

For more info about our services contact : help@bestpfe.com

Table of contents

Chapter 1:Introduction and literature review
1.1 Historical evolution of karst and dikes knowledge
1.1.1 Karst
1.1.2 Cavities and sinkholes
1.1.3 Dikes
1.2 Literature review
1.2.1 Mechanism of karst and cavities collapse
1.2.2 Formation and stability of cavities
1.2.3 Stability of dikes
1.3 Geo-risk methodology
1.4 References
Chapter 2: The case study (dikes of Val d’τrléans)
2.1 The dikes of Val d’τrléans
2.2 The Val d’τrléans site
2.2.1 Site presentation
2.2.2 Geological context
2.2.3 Hydrogeological context
2.3 Sinkholes and subsidence (historical information)
2.4 Mechanical properties of soils
2.5 Summary
2.6 References
Chapter 3: Effect of the dike upon the stability of the cavity
3.1 Introduction
3.2 Analytical approach of cavity collapse
3.3 Dike effect upon the stability of cavity
3.4 Calculation of the dike effect
3.5 Results analysis and discussion
3.6 Summary
3.7 References
Chapter 4: Effect of cavity upon the stability of the dike slope
4.1 Introduction
4.2 Method and objective
4.3 Slope stability analysis
4.3.1 The Ordinary method of slices
4.3.2 Verification of TALREN results
4.3.3 Initial safety factor of the dike of Val d’τrléans (without cavity)
4.4 Modified method with a cavity underneath the dike
4.5 Application to the Val d’τrléans dike: safety factor of slope stability
4.6 Summary
4.7 References
Chapter 5: Numerical modelling (2D and 3D)
5.1 Objective and method
5.2 General description of the dike of Val d’τrléans model in CESAR-LCPC
5.3 Slope stability calculation by the c-phi reduction method
5.3.1 The theoretical bases of the method
5.3.2 Slope stability calculation for the dike without cavities
5.3.3 Slope stability calculation for the dike with cavities
5.4 Calculation by standard method
5.4.1 Effect of the cavity on the slope stability
5.4.2 Effect of the dike upon the cavity stability
a-Safety factor criterion
b-Vertical displacement criterion
c-Plastic strain criterion
5.5.1 Cavity underneath the centre of the dike
5.5.2 Cavity underneath the dike slope
5.5.3 Effect of the direction of the cavity
5.6.1 Cavity stability and collapse shape
5.6.2 Cavity effect upon the dike slope stability
5.7 Summary
5.8 References
Chapter 6:Expected scenarios due to collapsed cavity underneath a dike
6.1 Introduction
6.2 Scenario of isolated karstic caves
6.2.1 Scenario for one cohesionless alluvium layer
6.2.2 Scenario for one cohesive alluvium layer
6.2.3 Scenario for two alluvium layers
6.3 Scenario for cave connected to a karstic conduit
6.3.1 Scenario for one cohesionless alluvium layer
6.3.2 Scenario for one cohesive alluvium layer
6.3.3 Scenario for two alluvium layers
6.4 Water pressure effect and the final form of the cavity collapse
6.4.1 Resistance force against the water flow Ff
6.4.2 water flow force F
6.4.3 Application to the Val d’Orléans case
6.5 Summary
6.6 References
Chapter 7: General conclusion and perspectives
7.1 General conclusion
7.2 Perspectives
7.1 Conclusion générale
7.2 Perspectives