Samenvatting
Introduction to bed, bank and shore protection Engineering the interface of soil and water The interface of land and water has always played an important role in humanactivities; settlements are often located at coasts, river banks or deltas. When the interface consists of rock, erosion is usually negligible, but finer material can make protection necessary. In a natural situation, the interface moves freely with erosion and sedimentation. Nothing is actually wrong with erosion, unless certain interests are threatened. Erosion is somewhat like weed: as long as it does not harm any crop or other vegetation, no action is needed or even wanted. There should always be a balance between the effort to protect against erosion and the damage that would occur otherwise. Moreover, it should be kept in mind that, once a location is protected along a coast or riverbank that has eroded on a large scale, the protected part can induce extra erosion and in the end the whole coast or bank will have to be protected. So, look before you leap, should be the motto. A lot of cases remain where protection is useful. Along canals, rivers and estuaries, bank protection is often needed to withstand the loads caused by flow, waves or ships. Shore protection structures include seawalls, revetments, dikes and groynes. Bed protection is necessary where bottom erosion could endanger structures, like bridge piers, abutments, in- or outlet sluices or any other structures that let water pass through. Contents: 1. Introduction • 2. Flow - Loads • 3. Flow- Stability • 4. Flow - Erosion • 5. Porous Flow - General • 6. Porous Flow - Filters • 7. Waves - Loads • 8. Waves - Erosion and stability • 9. Ships • 10. Dimensions • 11. Protections 12. Environment • 13. Construction • Appendix A: Materials properties • Appendix B: Examples • Symbols • References • Index
Thuiswinkel Waarborg