Instrumentation of flood defence banks along the river thames. In field instrumentation in geotech. Engng. Proc.

Following upon the severe flooding from an exceptional tide cum surge in February 1953 a removable flood barrier in Long Reach was considered as the basis of a flood defence system compatible with the navigation interests yet avoiding the high cost of bank raising in the metropolis. Three designs of barrier were developed and costed, each embodying two 150 m wide navigation openings. The preferred system incorporated drop gates supported on high towers above shipping when not in use. The navigation authorities ruled that an unobstructed opening at 425 m was necessary and a new design exercise found in favour of retractable barrier structures but at increased cost with less reliability in performance. The formation of the Greater London Council led to a wider investigation of possible barrier sites and the lesser use by shipping of reaches above the Royal Docks permitted narrower openings. Schemes for some six different sites and over 40 variations in span arrangement were investigated and led to a proposal for four 60 m navigation openings in Woolwich Reach which might be closed by a form of rising section gate. This has proved to be the cheapest, most reliable and quickest to install of all the schemes investigated and is now the basis of design for contract.


2011 ◽  
Vol 15 (2) ◽  
pp. 327-346 ◽  
Author(s):  
Simon P. G. Hoggart ◽  
Robert A. Francis ◽  
Michael A. Chadwick

2021 ◽  
Vol 32 ◽  
pp. 100289
Author(s):  
Thomas van der Pol ◽  
Jochen Hinkel ◽  
Jan Merkens ◽  
Leigh MacPherson ◽  
Athanasios T. Vafeidis ◽  
...  

2012 ◽  
Vol 49 (11) ◽  
pp. 1267-1284 ◽  
Author(s):  
Olajide Samuel Oshati ◽  
Arun J. Valsangkar ◽  
Allison B. Schriver

Earth pressure data from the field instrumentation of a cast-in-place reinforced rectangular box culvert are presented in this paper. The instrumented culvert is a 2.60 m by 3.60 m double-cell reinforced cast-in-place rectangular box buried under 25.10 m of fill constructed using the induced trench installation (ITI) method. The average earth pressure measured across the roof was 0.42 times the overburden pressure, and an average of 0.52 times the overburden pressure was measured at mid-height of the culvert on the sidewalls. Base contact pressure under the rectangular box culvert was also measured, providing field-based data demonstrating increased base pressure resulting from downward drag forces developed along the sidewalls of the box culvert. An average increase of 25% from the measured vertical earth pressures on the roof plus the culvert dead load (DL) pressure was calculated at the culvert base. A model culvert was also tested in a geotechnical centrifuge to obtain data on earth pressures at the top, sides, and base of the culvert. The data from the centrifuge testing were compared with the prototype structure, and the centrifuge test results agreed closely with the measured field prototype pressures, in spite of the fact that full similitude was not attempted in centrifuge testing.


Author(s):  
P. G. Whitehead ◽  
J. Crossman ◽  
B. B. Balana ◽  
M. N. Futter ◽  
S. Comber ◽  
...  

The catchment of the River Thames, the principal river system in southern England, provides the main water supply for London but is highly vulnerable to changes in climate, land use and population. The river is eutrophic with significant algal blooms with phosphorus assumed to be the primary chemical indicator of ecosystem health. In the Thames Basin, phosphorus is available from point sources such as wastewater treatment plants and from diffuse sources such as agriculture. In order to predict vulnerability to future change, the integrated catchments model for phosphorus (INCA-P) has been applied to the river basin and used to assess the cost-effectiveness of a range of mitigation and adaptation strategies. It is shown that scenarios of future climate and land-use change will exacerbate the water quality problems, but a range of mitigation measures can improve the situation. A cost-effectiveness study has been undertaken to compare the economic benefits of each mitigation measure and to assess the phosphorus reductions achieved. The most effective strategy is to reduce fertilizer use by 20% together with the treatment of effluent to a high standard. Such measures will reduce the instream phosphorus concentrations to close to the EU Water Framework Directive target for the Thames.


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