上海软土各向异性弹塑性模型

根据同济大学真三轴仪所做的上海典型软土的排水试验、Kirkgard和Lade真三轴仪所做的旧金山湾淤泥的不排水试验资料，以及日本太田—关口(0hta—Sikiguchi)模型，提出上海各向异性弹塑性模型(简称上海软土模型)，该模型包括形状函数、屈服函数、应力—应变关系。为了证明模型的合理性，从理论和试验中对形状函数和屈服函数进行了检验。最后，提供了上海软土模型的有关参数。     

清江茅坪滑坡白岩危岩体崩塌现场测量及其分析

位于茅坪滑坡体后缘的白岩危岩体于2002年8月24日发生了大规模的崩塌。崩落的块石落在滑坡体上，对滑坡体产生了加载作用，影响了该滑坡体的稳定性。为研究茅坪滑坡体的稳定性，有必要弄清滑坡体上崩落块石的堆积情况。论文在对清江隔河岩水库白岩危岩体崩塌现场调查的基础上，估算了崩塌岩体的体积，实地测量了岩体崩塌后堆积体表面块石的尺寸以及各块石空间位置坐标。对测量的结果进行了统计分析。根据所测量的块石尺寸、得到了崩落岩体的块体大小级配累积曲线图和各块石尺度出现的概率，从而阐明了各尺度崩落块石组合情况。根据各块石尺寸和各块石空间位置坐标、分析得到不同尺寸崩落块石落在滑坡体上的空间分布规律，从而为茅坪滑坡的进一步研究打下了基础。     

城市快速道路软基处理方案探讨

介绍了深厚软土地基地质条件及处理技术要求,进行了软基处理的技术经济对比并选择了相应方案。此外,对选择的方案进行了参数设计及沉降分析预测。该方案实施后,取得了明显的经济效益。     

软弱层带对似层状结构岩体强度参数的影响

通过对赋存于似层状结构玄武岩岩体中随机发育缓倾角软弱结构面的厚度、间距及连通状况的调查，分析了缓倾角软弱结构面对相应基本岩体强度参数各向异性的影响，并探讨了缓倾角软弱结构面连通率的求解方法，最后通过“连通率”和“厚度加权”法得到了水平和垂直的强度参数值。     

分形方法在南麂岛土地覆盖类型分析中的应用

借助分形理论对南麂列岛国家级海洋自然保护区内的主岛---南麂岛的地面覆盖及其状况进行分析,把各地类图斑的复杂性、破碎性和形状等定性概念,用分维值和形状因子进行定量描述和比较,分析其形成机制。结果表明,灌木林地和草地等自然性较强的地类分维值较大,而晒场和居民地等人为干预较多的地类分维值较小,庄稼地的分维值则介于它们之间。     

Tri-frequency spectrum method and results for resolving the parameters of Earth’s liquid core free nutation

The parameters of Earth free core nutation (FCN) are two relatively significant geophysical parameters. Sasao et al. (1980) and Wahr and Bergen (1986) provided the theoretical estimation values of FCN parameters. Gwinn, Herring and Shapiro (1987) first obtained the observational values of FCN parameters by very long base Interference (VLBI) at Cambridge University. In the same year, Neuberg and Zürn in former West Germany and Hinderer in France began to retrieve FCN parameters by the observation of gravity tides and introduced the stacking method. The other scholars who researched into the same geophysical problems by applying the data of gravity tides basically followed the stacking method. The results they reached were similar to the observational result of FCN parameters given by Neuberg et al. in 1987. But the observational results of FCN parameters gained from gravity tides were not identical with those from VLBI, mainly because of the large difference of quality of FCN. So there was not an affirmative observational result of FCN parameters since then. In this paper, The authors firstly introduce the tri-frequency spectrum method with clearly geometrical and geophysical meaning for the resolution of FCN parameters, and the observational results of FCN parameters obtained from tide data at three superconducting gravity stations were accordant with those from VLBI, which will be relatively important to arriving at a certain observational result of FCN parameters.     

Sub-Daily Earth Rotation Parameters and the International GPS Service Orbit/Clock Solution Products

Tidally induced sub-daily Earth Rotation Parameters (ERP) variations, when not properly accounted for, can cause apparent orbit and ERP rate errors, which can significantly exceed the IGS solution errors. All International GPS Service (IGS) Analysis Centers currently apply the conventional sub-daily ERP model in their transformations from ITRF (International Terrestrial Reference Frame) to ICRF (International Celestial Reference Frame), both of which are used for IGS global analyses. However, some IGS Analysis Centers did not apply the sub-daily ERP model when transforming ICRF orbit solutions to ITRF, which is used for IGS orbit/clock products. This transformation inconsistency can cause significant orbit RMS differences that could exceed the 5-cm level. Independent ERP rate solutions are sensitive even to small errors in the sub-daily ERP model, and can be used to verify the sub-daily ERP model at, or below 0.1 mas/day precision level.The Precise Point Positioning (PPP) via precise station position solutions with the IGS orbit/clock combined products, provides an ideal interface to access the IGS realization of ITRF. PPP also yields precise station clock and tropospheric zenith delays (TZD) solutions, all at the sub-cm precision level. However, when using IGS orbit/clock products it is important that the same convention be used with respect to sub-daily ERP. Otherwise, the solutions of station navigation positions, station clocks and TZD's will be affected by significant errors that could exceed the 1-cm level.     

Seismic Ground Motion Zoning Maps of the Pangxi Region

The seismotectonic environment and seismic activity in Southwest China region were studied based on new data and new results obtained during the Eighth and Ninth Five-Year Plans,the seismic areas and zones and potential seismic source zones were determined.and the relation between seismic activity parameters and ground motion attenuation was determined.Finally the seismic gound motion zoning maps of the Pangxi region was compiled by using the multi-parameter and multi-scheme method.     

Tri-frequency spectrum method and results for resolving the parameters of Earth's liquid core free nutation

The parameters of Earth free core nutation (FCN) are two relatively significant geophysical parameters. Sasao et al. (1980) and Wahr and Bergen (1986) provided the theoretical estimation values of FCN parameters. Gwinn, Herring and Shapiro (1987) first obtained the observational values of FCN parameters by very long base Interference (VLBI) at Cambridge University. In the same year, Neuberg and Zürn in former West Germany and Hinderer in France began to retrieve FCN parameters by the observation of gravity tides and introduced the stacking method. The other scholars who researched into the same geophysical problems by applying the data of gravity tides basically followed the stacking method. The results they reached were similar to the observational result of FCN parameters given by Neuberg et al. in 1987. But the observational results of FCN parameters gained from gravity tides were not identical with those from VLBI, mainly because of the large difference of quality of FCN. So there was not an affirmative observational result of FCN parameters since then. In this paper, The authors firstly introduce the tri-frequency spectrum method with clearly geometrical and geophysical meaning for the resolution of FCN parameters, and the observational results of FCN parameters obtained from tide data at three superconducting gravity stations were accordant with those from VLBI, which will be relatively important to arriving at a certain observational result of FCN parameters.     

Influence of earthquake frequency content on soil dynamic properties at CAO site

The installation of vertical downhole arrays in the field that record the soil behavior during earthquakes, has opened the opportunity of exploring another alternate method for assessing the soil dynamic properties by solving the inverse problem. This article proposes a methodology for solving this problem using spectral analysis of downhole arrays records. The one-dimensional shear wave propagation model was used, considering a homogeneous-viscoelastic medium. This methodology was applied at the site known as Central de Abasto Oficinas (CAO), which is located in the lake zone of the Mexico City. The results indicate that even relatively low frequencies have a noticeable effect on dynamic soil properties. Shear modulus increases and damping ratio lessens when the frequency rises.