Field monitoring

Field monitoring has been an integral part of the Soil Mechanics Section’s research activities since the early 1950s, primarily at that time with the instrumentation of various earth dams and slopes. Particularly important developments have been made in the measurement of pore water pressures and the design of grouts needed to seal-in piezometers. A major advance was made in the 1990s with the measurement of suctions using the Imperial College tensiometer (probe), providing much greater insight into slope stability, equalisation of pore pressures and seasonal cyclic responses.

Building and structural monitoring is another key activity, which is led by Dr. Standing. In early years the effect of consolidation settlements on building deformations was investigated. More recently, building and ground response to tunnelling and deep excavation-induced movements (short and long term) have been extensively investigated (e.g. for the JLEP, CTRL and Crossrail).

The Imperial College model Pile has been used extensively to investigate the development of pile res

istance in the short and longer term. Several full-scale piling research projects have been run to investigate, for example, the effects of using jet-grouted bases, the effects of tunnelling on exisiting piles and more recently the lateral response of driven piles. In all these cases the piles were heavily instrumented and the interpretation of the results has led to major steps forward in pile design (ICP design method, led by Prof. Jardine), time effects and redistribution of pile loads during tunnelling.

New technologies have been used and developed, sometimes in collaboration with others, e.g. ETH Zurich for optical fibre measurements and GeoObservations for SAA monitoring (Shape Accel Array). Recently the use of multi-level piezometers has been investigated.