| The foundation problems of super soft soil (silt, silty soil) can be processed with static and dynamic drainage consolidation method (SDDCM). The optimal design of static loading, dynamic loading and drainage system is the deciding factor. What is the static loading? How to exert dynamic loading? What is the dynamic loading? And what kind of drainage system is to be set? And what are the relationships with static loading, dynamic loading and drainage system. The answers of the questions are the key factors with SDDCM.Based on the previous studies, combine with engineering tests of muck ground treatment project in Guangzhou Nansha Titan Petrochemical an ultra-soft ground treatment works, the model of static loading, dynamic loading and drainage system is established according to the principle of the balance of forces. The model is verified from the static and dynamic triaxial tests, numerical simulation. The main contents and conclusions are as follows:1. Three major factors (static loading, dynamic loading and drainage system) are analyzed and summarized. The static loading, dynamic loading and drainage system can be optimal designed based on the changes of the soil indicators.2. Guided by the basic principles of consolidation with SDDCM, based on triangle transient loading, a model about mutual adaptation relationships of static loading, dynamic loading and drainage system is established according to the principle of the balance of forces. That is model reflects the mutual influence, mutual restraint, mutual adaptation relationship of static loading, dynamic loading and drainage system.3. The optimal design of static loading, dynamic loading and drainage system is described and the model parameters R is discussed. It can conlude that R not only can be used as trial ramming parameter which quantitatively and intuitively reflects the adaptive relationships. In addition, the parameters R can be used as evaluation parameters on muck foundation reinforcement effects.4. The model parameters are calculated combine with Guangzhou Nansha Titan Petrochemical an ultra-soft ground treatment works. It shows that the model has good applicability in engineering practice and provides the convenience for engineers.5. The mutual adaptation relationships are analysised from the angle of static and dynamic triaxial test adopted by the geotechnical engineering companies GCTS SPAX-2000static and dynamic (modified). The conclusions are as follows:①There is an optimal ratio between with soft soil overburden and soft soil with SDDCM; When the sample size is50mmx50mmx120mm at the indoor static and dynamic triaxial test, the thickness ratio of so ft soil overburden layer and soft soil layer can be controlled to1:5.②When the spacing of the drainage system is reduced to an optimal value, silt layer stress is the largest at the same sand cushion and impact frequency.③Laboratory tests proved that if the impact frequency is too high, it is not conducive to soil drainage consolidation for the rammer disturbance at the1-16HZ impact frequency.￤hen the sample size is50mm×50mmx120mm at the indoor static and dynamic triaxial test, the soil effective stress increased gradually with each pass tamping energy increases at the condition of30kPa confining pressure, a hole drainage system as and1HZ impact frequency.6. Based on the Guangzhou Nansha Titan Petrochemical field surveys and monitoring datas, the numerical simulation calculation was used MIDAS/GTS to study the mutual adaptation relationships. The conclusion is:①The influence distance of horizontal and vertical is close after tamping for soft soil overburden. The stress diffusion angle of soft soil overburden is about45.②The shape of the range of vertical settlement at horizontal plane is similar to the "crossroads". And the vertical settlement reduce from center to outer edge for good drainage system.③After a period of inactivity with impact, the loads can be transmitted deeply for the soft soil covering and drainage system. |
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