RESEARCH ON DYNAMIC TESTING APPLICATION OF DOUBLE-PILE-CAP FOUNDATIONS

The large-scale dynamic machine foundation, nuclear power foundation, land wind power foundation and other infrastructures are easily impacted by the machine disturbance, seismic action, wind load and other dynamic effects, under the action of dynamic load, vibrations of operating machines will cause vibrations of foundations, which will have great adverse impacts on foundations. It may greatly reduce the bearing capacity of foundation and lead to difference settlement of foundation, which may affect normal operation of machines, and might even cause serious accidents in severe cases. A double-pile cap foundation is one of the most common basic forms of these foundations. Combined with actual test projects, two groups of double-pile cap foundations with the same sizes and form but different layout directions were designed. Dynamic vibration characteristics of the two double-pile cap foundation under the action of the vertical, horizontal and torsional vibration were carried out by high-power mechanical vibration exciters under surface and embeded conditions, respectively, to compare the dynamic parameters of each double-pile cap foundation in different directions. The results showed that although the sizes and cap foundation shapes of for the two foundations were the same, but the different structural arrangement directions would have a great difference on dynamic parameters of foundations. The difference would affect design parameters of equipment foundations, so the direction arrangements of double-pile cap foundations should be considered in design of two-pile cap dynamic foundations.