| 1. | Analysis of parameters sensitivity of duncan - chang model
张模型参数敏感性分析 |
| 2. | Comparison of several methods for improving duncan - chang model
张模型几种改进方法的比较 |
| 3. | Improvement of duncan - chang nonlinear model and shen zhujiang ' s elastoplastic model for granular soils
张模型和沈珠江双屈服面模型的改进 |
| 4. | Based on the results mentioned above , the author modified the model , aiming at the shortage of the model . the modified model introducing damage variable takes soil ' s structure into account
本文结合室内试验结果，引入损伤的概念，考虑土的结构性，对邓肯?张模型进行了修正。 |
| 5. | Duncan - chang model , an non - linear elastic model , is widely used in engineering . because the model reflects the main rules of the deformations of soils , and parameters can be gained from triaxial tests
由于邓肯?张模型反映了土体变形的主要规律并且其各项参数易于从常规三轴试验求得而在工程实践中被广泛应用。 |
| 6. | Stress and deformation of computational analysis is usually not in conformity with actually observed data due to this reason in fem analysis of earth dam and crfd such as the extensively applied duncan - chang hyperbolic model , and many other models also equally have similar problem
如应用广泛的duncan ?张模型在土坝、面板坝有限元应力变形计算分析中就存在与实际观测值不一致、不合理的结果，许多模型也同样存在类似的问题。 |
| 7. | To meet the need of settlement calculation with fem when absence of laboratory triaxial test data in common road engineering , methods of determining the five parameters included in tangential elastic module through soil routine tests and the related emendation coefficient are given . at the same time , one approximately substituted formula for tangential poisson ratio is also developed , which is suitable for both sandy soil and cohesive soil . ( 3 ) research on main parameters modification of duncan - chang model based on the improved bp network
对于一般道路工程中不做三轴试验但须进行沉降有限元计算的情况，给出了依据土体常规试验的切线弹性模量确定方法和相关修正系数，同时也提出了对砂性土和粘性土均适用的切线泊松比的近似替代式子； ( 3 )基于改进的bp网络对邓肯张模型主要参数修正研究。 |
| 8. | The paper uses the coupled numerical method by combine the finite element method ( fem ) with the infinite element method ( iem ) to analysis the strength and deformation of the soil under the shallow foundation . the corresponding three - dimensional analytical program is devised by fortran9o computer language . in the program
本文即以有限元-无限元耦合的数值方法用fortran90语言编制了竖向荷载作用下浅基础地基的非线性、弹塑性三维分析程序，分析中采用的土的本构模型有非线性的邓肯-张模型、成都科大k - g模型和弹塑性的修正剑桥模型、殷宗泽双屈服面模型、 drucker - prager模型。 |
| 9. | That is to say , there are differences in selecting the points which represent the average compactive effect of soil between piles . based on cavity expansion method , the stress change of soil between piles when sinking pile is studied with elasto - plasticity theory . the triaxial compression tests of undisturbed samples are carried our in laboratory
本文通过圆孔扩张理论，应用弹塑性理论对灰土挤密桩成孔过程中桩间土土体应力的变化进行了分析研究，通过试验采取原状土样进行三轴试验，用邓肯-张模型建立土的本构关系，对桩间土的挤密进行理论分析，并通过现场干密度试验，分析和研究桩间土的挤密效果。 |
| 10. | The several ones that have more lager sensitivity to embankment settlement are found out . then , aimed at the traditional three - layer bp network ' s shortages : easily getting into local minimum value and slow convergence , the modification combined momentum method with self - adaptation study velocity is made , and one improved bp network is put forward . finally , according to the results from above sensitivity analyses , the nonlinear model main parameters of each natural layer in roadbed are approximately rectified using the improved bp network technology founded on its stronger nonlinear mapping capacity and the settlement measurements
采用非线性有限元程序，对邓肯-张模型中8个参数与路堤沉降的关系进行了详细分析，找到了影响沉降的主要参数；接着，针对传统的三层bp网络具有收敛速度慢、易陷入局部极小点等不足，对其进行了修正，提出了改进的bp神经网络模型；最后，根据上述灵敏度分析结果，基于改进的bp网络模型较强的非线性映射能力和前期沉降实测资料，对路基中各天然土层的非线性模型主要参数进行了反分析修正； ( 4 )路堤沉降计算一维法中考虑应力历史、侧向变形的研究。 |
