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排序方式: 共有71条查询结果,搜索用时 15 毫秒
1.
地质灾害治理工程项目管理是地质灾害管理的具体体现和实施过程,其基本任务是根据地质灾害管理目标和管理方法,组织实施防治工程,保障取得预期的减灾成果。就镇江市地质灾害治理工程项目管理目前现状,从规范文件、招标机构、管理工具、管理经验、干扰因素、风险评价、人员素质等方面进行粗浅分析,并针对存在的问题提出相应的对策,借以提高镇江市地质灾害治理工程项目管理的能力和水平,以便今后地质灾害治理项目管理更好地完善和发展。 相似文献
2.
本文从招标投标工作取得的成绩入手,分析了目前招投标工作存在的问题。从严格招标代理机构管理、加强招标文件和合同备案管理、规范评标专家评标行为、推行量化评分办法、建立投标人诚信档案、畅通投标人报名渠道,规范投标资格预审工作等方面提出了加强和改进工程招标投标监管工作的思路。 相似文献
3.
The paper deals with stress-release effects induced by man-made cuts or excavations into natural stiff clay slopes that experienced erosion in response to valley deepening. The study was focused on the Monte Mario hill in Rome (Italy), which formed part of an area of recent urban expansion. The methodology of the study relied on a reference engineering-geology model, which was developed on the basis of site and laboratory data and stress–strain analyses. The latter analyses were carried out with the finite-difference code FLAC 4.0. Numerical modelling was based on a sequential approach, taking into account the main evolutionary stages of the Tiber river valley in Romeȁ9s urban area and then making cuts at the bottom of the slope located south of the Monte Mario Astronomical Observatory. The simulation revealed the stress-release effects that fluvial erosion and excavation fronts have caused on the investigated slopes and their consequent gravitational instabilities. These processes appear with metre-scale displacements, followed by stress-release cracks (actually observed on the slopes under review). In quantifying stress-release deformations, the simulation took into account the possible role of creep in the observed retardation of stress-release effects.Research activities were carried on with the co-operation of Dȁ9Arcangelo A. (Consorzio TREESSE, andrea.darcangelo@libero.it) and Moretti S. (IMG S.r.l. Servizi Tecnici per lȁ9Ingegneria e lȁ9Ambiente, moretti@img-srl.it) 相似文献
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Geoid, topography, and the Bouguer plate or shell 总被引:1,自引:1,他引:1
Topography plays an important role in solving many geodetic and geophysical problems. In the evaluation of a topographical
effect, a planar model, a spherical model or an even more sophisticated model can be used. In most applications, the planar
model is considered appropriate: recall the evaluation of gravity reductions of the free-air, Poincaré–Prey or Bouguer kind.
For some applications, such as the evaluation of topographical effects in gravimetric geoid computations, it is preferable
or even necessary to use at least the spherical model of topography. In modelling the topographical effect, the bulk of the
effect comes from the Bouguer plate, in the case of the planar model, or from the Bouguer shell, in the case of the spherical
model. The difference between the effects of the Bouguer plate and the Bouguer shell is studied, while the effect of the rest
of topography, the terrain, is discussed elsewhere. It is argued that the classical Bouguer plate gravity reduction should
be considered as a mathematical construction with unclear physical meaning. It is shown that if the reduction is understood
to be reducing observed gravity onto the geoid through the Bouguer plate/shell then both models give practically identical
answers, as associated with Poincaré's and Prey's work. It is shown why only the spherical model should be used in the evaluation
of topographical effects in the Stokes–Helmert solution of Stokes' boundary-value problem. The reason for this is that the
Bouguer plate model does not allow for a physically acceptable condensation scheme for the topography.
Received: 24 December 1999 / Accepted: 11 December 2000 相似文献
6.
地质档案原本是地勘单位开展地质工作的重要基础资料,大多是孤本,非常宝贵,但原始资料的立卷归档工作往往不够重视。笔者结合本单位的实际,从存在问题、解决问题中进行分析探讨,并提出解决地质资料立卷归档的主要途径。 相似文献
7.
Jiang Wali 《中国地震研究》2007,21(2):130-138
The tectonic characteristics and research problems of five earthquakes with M≥7.0 on the North China Plain over the last 300 years are addressed in the paper, including the cognition that there were no ground fractures in the 1966 Xingtai earthquake, the question caused by the thrust activity of the seismic fault of the Tangshan Earthquake and the discussion of the seismotectonic environment of the 1830 Cixian earthquake and the 1937 Heze earthquake. The author thinks that the main reason for the problems in research of strong earthquake tectonics in the region is that the status of activity of the main tectonics during the Late Quaternary are unknown. This affects the founding of discrimination criteria for seismotectonics of strong earthquakes on the North China Plain. Discriminating the Holocene active faults from the large number of faults is the most effective method for seismic hazard assessment in the area in future. 相似文献
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10.
José Edmundo Mansilla 《Celestial Mechanics and Dynamical Astronomy》2006,94(3):249-269
Results are obtained about formal stability and instability of Hamiltonian systems with three degrees of freedom, two equal
frequencies and the matrix of the linear part is not diagonalizable, in terms of the coefficients of the development in Taylor
series of the Hamiltonian of the system. The results are applied to the study of stability of the Lagrangian solutions of
the Three Body-Problem in the case in which the center of mass is over the curve ρ*, on the border of the region of linear stability of Routh. The curve ρ* is divided symmetrically in three arcs in such a way that if the center of mass of the three particles lies on the central
arc, the Lagrangian solution is unstable in the sense of Liapunov (in finite order), while if the center of mass determines
one point that lies on one of the other two arcs of ρ*, then the Lagrangian solution is formally stable. 相似文献