Discussion. Design and Construction of the Northfleet Hope Container Terminal, Til -Bury Docks.

Abstract

. MILLS M r Page, M r Curtisand M r Mills Regarding the test on the sheet piling, some additional information may be of interest. The loads in four of the tie rods were monitored: two of these rods were instrumented at both quay and anchorage ends and two at the quay ends only.Figs 21 and 22 show that the loads in the quay ends were quite low initially at only 100-200 kN and it was not until the final placing of the 2 m of Thanet sand compacted in 30 cm layers, that the loads increased to 400-500 kN, about two thirds of the 700 kN design load. From Fig. 22 it appears that initially the anchorage loads were dissipated in friction along the rod without any load being transmitted to the anchorage, the rods being under temporary compression at this end.81. A Stothert & Pitt 6 t vibrating roller (developing 96 t impact load) was used to compact the sand and this clearly helped to generate more realistic earth pressures transmitting loads of up to 40 t to the anchorages. If the design had been of the form in which the sheeting was driven entirely through existing soil with the face dredged after completion it is possible that the anchorage loads would have remained low, suggesting an unnaturally high factor of safety.82. Nine piezometer tubes were also installed to monitor movement of groundwater level. Only one of these continued to function throughout the construction period and this happened to be nearest to the instrumented sheet piles. A typical result is given in Fig. 23. This shows groundwater level following the rising tide very closely, which may not be entirely accurate, and could have been distorted by the presence of the piezometer tube itself. With the falling tide, groundwater level is held just below mid-tide and this is probably a true indication of the situation at this section. The design was based on groundwater being at mid-tide level and to that extent appears to be slightly conservative.M r J. N. Black, PLA, Tilbury Docks There were several reasons for choosing a site on the riverside rather than within the dock. The third-generation container ships were just beginning to be built, and we felt it would be advantageous to have a facility which obviated the need for them to go through the lock : the time-saving was important, as most of the large ships using Tilbury have to use the tide for the depth of water. Another reason was