履带式挖掘机配置回转减速机的产品特点及技术性能开发探析

挖掘机作为主要的土方机械对当前的建设．Y-程具有举足轻重的作用，近年来，随着现代建设工程的发展步伐加快，挖掘机产品的开发也得到了突破性的发展。当前工程建设中，挖掘机是必不可少的机械工具。该文对履带式的挖掘配置的回转减速机产品进行产品特点的描述，并对其性能开发进行简要的探析，以促进现代土方建设更大发展。

The construction design and practice of Three Gorges Project

The construction of Three Gorges Project (TGP) is characterized by large construction scale,high construction intensity and complexity in technology.In view of various technical difficulties such as navigation in construction period,two river closures,high-intensity concrete and earth-rock construction,high-intensity construction and demolition of RCC (roller compacted concrete) cofferdam in stage III and immediate navigation of double-line five-step shiplock after impoundment of reservoir,the scheme of river diversion during construction is adopted,namely "diversion in 3 stages,open channel navigation and cofferdam power generation".The practice and innovation achievements in river diversion during construction as well as earth-rock and concrete construction are presented emphatically.

Stability analysis of slope in strain-softening soils using local arc-length solution scheme

Soils with strain-softening behavior — manifesting as a reduction of strength with increasing plastic strain — are commonly found in the natural environment. For slopes in these soils,a progressive failure mechanism can occur due to a reduction of strength with increasing strain. Finite element method based numerical approaches have been widely performed for simulating such failure mechanism,owning to their ability for tracing the formation and development of the localized shear strain. However,the reliability of the currently used approaches are often affected by poor convergence or significant mesh-dependency,and their applicability is limited by the use of complicated soil models. This paper aims to overcome these limitations by developing a finite element approach using a local arc-length controlled iterative algorithm as the solution strategy. In the proposed finite element approach,the soils are simulated with an elastoplastic constitutive model in conjunction with the Mohr-Coulomb yield function. The strain-softening behavior is represented by a piece-wise linearrelationship between the Mohr-Coulomb strength parameters and the deviatoric plastic strain. To assess the reliability of the proposed finite element approach,comparisons of the numerical solutions obtained by different finite element methods and meshes with various qualities are presented. Moreover,a landslide triggered by excavation in a real expressway construction project is analyzed by the presented finite element approach to demonstrate its applicability for practical engineering problems.

探究城市竖向设计

结合区域现状地形地貌地物,通过阐述竖向设计的原则、作用、方法、深度、注意事项等内容,统一分析了区域内道路、排水、不同场地等的适用坡度,以利于建(构)筑物的布置与空间环境的设计,从总体上控制区域的竖向高程,使区域的建设整体效果更加优美。

公路路基施工技术与质量控制措施

在道路交通工程建设中,公路工程质量的好坏直接关系着整个道路交通工程的运行情况。其中,在公路工程建设中,路基施工是最基础的内容之一,只有确保路面基础工程质量,才能保证公路工程顺利施工。在公路工程路基施工过程中,涉及到的相关工作主要包括路面设计、道路施工、工程质量监测、路面维护等多方面内容。由于在公路路基施工过程中,施工难度和内容较为复杂,涉及到的技术和内容较广,因此该工程属于综合类项目,对相关的路基施工技术要求较高,其中,路基结构建设是整个公路路基施工的基础项目,只有确保路基结构建设顺利开展,才能确保整个项目有效建成。