A study on the properties and modification test of the dredged material of an urban river

The dredged material (DM) of Qinhuai River, Nanjing, was taken as an example. Through the basic geotechnical tests with XRD and Xray fluorescence spectrometer, the basic physical properties, mineral composition, chemical compositions of the material were studied, respectively. The results show that the DM of the Qinhuai River has a very low content of clay, its organic matter content is very high; mineral composition are mainly composed of quartz and clay minerals. In order to study resourcereusing treatment of DM，cement and lime were added to solidify the soil for comparison. The unconfined compressive strength (UCS) tests indicate that with the increasing cement content, the failure of cementsolidified soils are converted from plasticity to brittle in failure strain of 1.8% to 2.2%，while all the limesolidified soils of about 1%.The UCS value of 28d cementsolidified soil is only 670 kPa. The curing effect of cement is better than that of lime, but its strength is lower than the cementsolidified strength of general soft clay. The research result is beneficial to the disposal of DM of urban river.