Beneficial Inner-City Quay Walls?

Inner-city quay walls in public urban areas: expense or added value? These civil structures approach, reach or exceed the end of their life span. This threatens the quality of the public urban area. Many municipalities are still willing to invest in the management of inner-city quay walls, despite the costs. Apparently, the quay walls generate more benefits than that are initially expected based on their original functions. Until now, municipalities have failed to determine the added value of inner-city quay walls. Theoretical and practical research suggests that adequate asset management is indispensable. Nevertheless, no research focuses on valuable management of inner-city quays, in terms of performance, costs, benefits and risks. How to decide on a management strategy that adds the most value to the public area? A new framework should identify and incorporate the value of inner-city quay walls in the management process

Three-dimensional dento-skeletal effects of mandibular midline distraction and surgically assisted rapid maxillary expansion:A retrospective study

It was the aim of the study to provide a three-dimensional evaluation of dento-skeletal effects following bone-borne vs tooth-borne mandibular midline distraction (MMD) and tooth-borne surgically assisted rapid maxillary expansion (SARME). A retrospective observational study was conducted. Cone beam computed tomography (CBCT) records were taken pre-operatively (T1), immediately post-distraction (T2) and 1 year post-operatively (T3). All included 30 patients had undergone MMD (20 bone-borne MMD; 10 tooth-borne MMD). A total of 20 bone-borne MMD and 8 tooth-borne MMD patients had simultaneously undergone tooth-borne SARME. At T1 vs T3, canine (p = 0.007; 26.0 ± 2.09 vs 29.2 ± 2.02) and first premolar (p = 0.005; 33.8 ± 2.70 vs 37.0 ± 2.43) showed significant expansion on the tip level for tooth-borne MMD. This was no significant on the apex level, indicating tipping. Bone-borne MMD showed a parallel distraction gap, whereas tooth-borne MMD showed a V-shape. There was a significant (p = 0.017; 138 ± 17.8 vs 141 ± 18.2) inter-condylar axes increase for bone-borne MMD. In conclusion, bone-borne vs tooth-borne MMD and tooth-borne SARME showed stable dento-skeletal effects at 1 year post-operatively. Bone-borne and tooth-borne MMD seemed not to be superior to each other. The choice of distractor type therefore depends more on anatomical and comfort factors.</p

The Importance of Hydraulic Structures for Society: Quay Walls and Dikes in the Netherlands

Since mankind exists, men have undertaken engineering activities to make their life more pleasant and secure. However this has not been an easy task, especially in the past. The knowledge of mathematics and physics to describe engineering problems became available only since 1400-1500. Nevertheless, great achievements have been made by man before that time, e.g. the pyramids in Egypt, the first sluice in China, the Borobudur temple in Indonesia, and the design and building activities of the Inca’s in South America. To illustrate this development, also the world economy, world ecology will be shortly mentioned. The structures that are briefly discussed in this paper are: soil and concrete dams for generating electricity, reservoirs for irrigation and drinking water, dikes, sluices, inland and sea, tunnels, and quay walls. This paper presents an overview of hydraulic structures in general with the emphasis on quay walls and dikes in the Netherlands. Examples of these structures will be discussed illustrating present state of the art and also with a view to the future. Conclusions and recommendations are given to enhance the knowledge of hydraulic structures

Structures in hydraulic engineering: Port Infrastructure

In history harbours were places of 'natural' shelter, ships could be safely anchored, however loading and unloading facilities were generally non existent apart from human labour. On the other hand ports are man made places of shelter purpose built for efficient transfer of cargo. The distinction between the words harbour and port is not always clear cut, obviously many of today's ports once started out as harbours. In the past and nowadays ports play an important role in world trade, they are part of a logistic chain transporting cargoes all over the world. Four main cargo commodities can be distinguished, viz. containers, liquid and dry bulk, and breakbulk or general cargo. The difference shows in the type of vessel being used for maritime transport, the type of handling equipment and storage within the port, and the type of hinterland transport. General reference is made to the courses CT4330 and CT5306 on Ports and Waterways. The port has to provide shelter and facilities for cargo transfer. The subject of these lecture notes is the port infrastructure that is predominantly required for cargo transfer, i.e. quays and jetties. One could always argue that (e.g.) a breakwater provides the necessary protection to be able to moor a ship along a jetty, however, the breakwater will not unload the LNG carrier whilst there will always be a weather window allowing the LNG carrier being handled at the jetty. Nowadays port infrastructure types will be described and discussed with regard to structural design and wherever possible a glimpse on the future will be revealed as developments do not stop. Some specific subjects like fendering and scour in front of the port structures will be dealt with as well.Civil Engineering and GeosciencesHydraulic Engineerin

A History of Quay Walls: Techniques, types, costs and future

Hydraulic EngineeringCivil Engineering and Geoscience

Stuctures in hydraulic engineering: Port Infrastructure

Lecture notes on the planning and design of port infrastructure, like quay walls as gravity structures, sheet-piles, jetties and ro-ro facilties; anchoring of walls. Discussion of the loads on quay walls, jetties and dolphins. Construction of quay walls. Risk analysis, fender design. Scour problems in front of quay walls.Civil Engineering and GeosciencesHydraulic Engineerin