| With the development of large-scale and deep-water wharf construction,the construction examples of deep foundation trough gravity wharf projects have been increasing year by year.Through the observation data of existing engineering examples,it is found that for the rubble-bedding of deep foundation trough gravity wharf,even if the foundation trough is excavated to the bedrock,the settlement in the later stage of the wharf is still large,which seriously affects the stability of the wharf structure and brings great inconvenience to the loading and unloading operation of the wharf.At present,there are few studies on the settlement and deformation of rubble-bedding,so it is necessary to study the settlement and deformation of rubble-bedding(especially deep foundation trough rubble-bedding)during the construction period and later use stage.In this paper,the method of physical test、numerical simulation and field observation data analysis are used to study the calculation of settlement and deformation of rubble-bedding.The main work and conclusions are as follows:(1)Based on the principle of equal settlement of rubble-bedding,the concept of equivalent stress of foundation bed tamping is put forward.In view of two common foundation bed tamping processes,a model and method for calculating the settlement and deformation of rubble-bedding are put forward.(2)The vertical loading test of rockfill body is carried out to explore and clarify the law of vertical stress distribution in rockfill body.Through several groups of rockfill loading tests with different initial porosity,it is found that with the increase of initial porosity,the vertical additional stress in rockfill body attenuates faster along the horizontal direction.(3)The finite element model corresponding to the loading test of rockfill body is established and compared with the results of physical model test,which verifies the rationality of the parameter setting of the finite element model.Based on Jinjing4# berth project of Fuzhou Port,the finite element model of the wharf section is established,and the vertical stress distribution of the rubble-bedding in different periods is calculated.By comparing the finite element calculation results with the code calculation results,it is found that there is a great difference between them,which may be due to the fact that the backfill behind the wall and other factors are not considered in the code,so it is recommended to use the finite element method to calculate the vertical stress in the deep foundation trough rubble-bedding.(4)The settlement data of all caisson sections of Jinjing4# berth of Fuzhou Port are collated and analyzed,and combined with the field measured data of explosive compaction of rubble-bedding,the equivalent stress of explosive compaction and deformation modulus of rubble-bedding are calculated by inversion,it is found that the rubble-bedding will still produce a certain amount of settlement during the service life of the wharf.At the same time,the influence of various parameters on the settlement and deformation of foundation bed is analyzed,and according to the calculation method and mechanism of settlement deformation,it is put forward that the settlement and deformation of riprap foundation bed can be controlled from three aspects: improving the tamping effect of foundation bed,improving the quality of foundation stone and reserving settlement. |
