压缩破坏机制控制下非线性圆孔扩张问题能耗分析方法研究

The main research topics as followed: (1) using a large deformation theory, revealing the soil deformation mechanism of nonlinear cavity expansion process controlled by the compressive failure mechanism. (2) Conservation equations of energy and volume change during expanding are established according to the energy and the volumetric change conservation principle. (3) The method of energy dissipation analysis for non-linear soil cavity expansion problems was gained by using conservation of energy and volumetric change conservation equation, large deformation theory and the generalized non-linear failure criterion. The failure mechanism controlled by compression during expanding was revealed. The stress and strain field, the pore water pressure and the cavity expansion pressure were obtained variation by the method of energy dissipation. (4) In order to confirm the effectiveness of new method, several results of local test were compared. Through this project research, energy dissipation analysis method can be gained, and can provide a new idea for studying the cavity expansion problem.

传统的圆孔扩张理论因忽略其压缩破坏机理，制约了沉桩、注浆等工程应用，而能耗分析方法则是揭示其压缩破坏机理的有效方法之一。本课题的主要研究内容有：(1)采用大变形理论，揭示压缩破坏机制控制下非线性圆孔扩张过程中的土体变形机制；(2)利用圆孔扩张过程中的能量守恒和体变守恒原理，建立能量守恒与体变守恒方程；(3) 利用能量守恒与体变守恒方程、大变形理论与广义非线性强度准则，建立非线性土体圆孔扩张问题的能耗分析方法，揭示圆孔扩张问题的压缩破坏控制机理，阐明压缩破坏机制控制下非线性大变形圆孔扩张时的应力场、应变场、孔隙水压力和扩孔压力的变化规律；(4)将新方法应用于工程实践，证实其有效性，并进一步完善其可操作性。通过本项目的研究，能够提出压缩破坏机制控制下圆孔扩张问题的能耗分析方法，将在圆孔扩张问题的理论研究方面取得新进展，为分析圆孔扩张问题提供新的思路和理论依据。

传统的圆孔扩张理论因忽略其压缩破坏机理，制约了沉桩、隧道开挖和注浆等工程应用。本项目主要采用了能耗分析方法则揭示了圆孔扩张压缩破坏机理。通过本项目的研究，阐明了广义非线性土体大变形圆孔扩张问题的压缩破坏控制机理、构建了压缩破坏机制控制下非线性岩土土体大变形圆孔扩张问题的能耗分析方法、揭示了非线性土体圆孔扩张过程中的能量耗散机制、明确了岩土土体的应力应变非线性特性和大变形关系、确立了压缩破坏机制控制下非线性岩土土体大变形圆孔扩张问题的发生、发展机理，为分析压缩破坏机制控制下非线性岩土土体大变形圆孔扩张问题提供了新思路。