Experiment Study On Dynamic Characteristics Of Marine Sediments From Zhoushan Fishery Under Cyclic Loading

The foundation of Zhoushan Islands promotes the development of Sino south-eastzones. The local infra-structures, however, are still of shortage. Hence, marine structuresand civil engineering cases, such as ports, bridges, offshore platforms etc are within theplan. The key geo-technical data are not enough to help engineers accomplish thesecomplicated constructions. Therefore, valuable are the dynamic characteristics studies onlocal marine strata under cyclic loading. Accordingly, the primary dynamic tests wereapplied for Zhoushan undisturbed soil samples by GDS tri-axial system and resonantcolumn system. Here are the main results:The cyclic tri-axial tests were applied under strain control as well as stress controlconditions. The tests’ programs incorporate the comprehensive factors inclusive of theexciting amplitudes of strain and stress, confining pressure, consolidation ratio, cyclictimes etc. With the systematic tests’ programs, simulated are the dynamic response fields ofmarine soil including dynamic stress, dynamic strain, dynamic pore pressure and dynamicstrength etc. The evolution rule and characteristics on the dynamic response fields ofmarine soil were analyzed. The development mechanism of dynamic elastic moduli anddamping ratio were studied.The resonant column tests were carried out to simulate the mechanism of dynamicshear moduli, damping ratio and shear wave velocity under the comprehensive programsinclusive of exciting frequencies and dynamic shear strain etc. The systematic dynamiccharacteristics on Zhoushan marine strata were analyzed with the comparison of cyclictri-axial tests and resonant column tests results. The dynamic strain interval was enlargedup to10-6-10-2with these tests.The backbone curves of Zhoushan marine strata were established with hyperbolicmodels. Some models are helpful for simulation on softening effects on marine strata.The referential values on key dynamic parameters of Zhoushan marine strata were offeredbased on the systematic tests’ studies. These results play an important role for engineeringapplication and academic business.