Theoretical Applications And Development Of Multi-Mechanisms Thermodynamical Approaches To Rate-independent Dissipative Geomaterials

It is obviously that the single deformation mechanism cannot satisfy the needs for describing geomaterials complicated behaviour.Based on the First/Second Law of Thermodynamics,a systematic constitutive presentation of 32 possible ways within the multi-mechanisms thermodynamical framework for rate-independent geomaterials description is built in part I.The proposed multi-mechanisms thermodynamical framework assures to develop the coherent,compact and open system to simulate concrete behaviour for geomaterial without violate the Law of Thermodynamics. Application examples and the restrict conditions are discussed in detail separately for the proposed framework in appendix.Several integration schemes are investigated and evaluated for the new approach.It appears that a series of these basic studies is helpful to build rational governing equations for geotechnical materials.By the series of theory work built in part I,the innovative idea of multi-mechanisms thermomechanical approach is proposed to develop the families of models to describe the multi-mechanisms response for rate independent frictional dissipative geomaterials.As an application of the new method,the concrete series of models are developed in the part II.Account for the structural damage and dissipative nature of soil,the damage and structural rearrangement behaviour are chosen to present the concrete multi-mechanisms modeling methods for geomaterial.Model prediction results fit the GDS and conventional experimental data of Zhengzhou and Beijing naturally clay very well.It indicates that the proposed isotropic hyperplastic structural damage dual-surface model effectively can be used in describing the bearing capacity for some structured soils.To reflect more real stress characteristic description,a three-dimensional model is realized by introduced the generalized non-linear strength theory in chapter 5.To take frictional and anisotropy response into account,a rotational hardening model is proposed in chapter 6 by following the multi-mechanisms thermodynamical approach. Through evaluation and compared the model simulation to the experimental results,the applicability of the series of proposed models are preliminary validated.It shows that the rational estimation ability for predicting the deformation of the hardening granule geomaterials in the condition of small strain scope and low confine pressure.The practicability and availability of the multi-mechanisms thermodynamical approach was indicated farther.The summarization and expectation of future research in modeling method for geomaterials are presented in the partâ…¢of the paper.The series of models in proposed approach satisfy the laws of thermodynamics and possible can account for more structural or complicated factors for soil behaviour description.It is believed that the proposed new energy approach would help better understand for more perplexing aspects of soil behaviour and the further application of the proposed approach should be developed in the next step.