A three dimensional embedded beam element for reinforced geomaterials

This paper presents the formulation and verification of a 3D embedded beam element, which is intended for numerical modelling of three dimensional problems concerned by reinforced geomaterials. This element permits analysis of reinforced geomaterial structures with simplified meshes, that do not need to account for reinforcement orientation. The paper is composed of four sections. Section 1 discusses the need for the development of a particular beam element for soil reinforcement, which can be easily used in practical applications. Section 2 describes the mathematical formulation of this element, while Section 3 deals with its verification on various examples. Section 4 illustrates an application of this element by analysing the behaviour of a group of micropiles containing inclined elements and subjected to lateral loading. Copyright © 2004 John Wiley & Sons, Ltd.     

预应力锚索框架地梁的互作用变形耦合分析

由于压缩变形的传播效应,预应力锚索框架地梁与边坡各接触点之间存在互作用变形的耦合效应,而现有预应力锚索框架地梁分析方法大多忽略了地梁基底接触点之间的相互影响。从可考虑变形传播效应的弹性半空间地基理论出发,建立预应力锚索框架地梁与边坡岩土体不同接触点之间的互作用变形耦合分析模型,并通过实例对比分析表明,考虑互作用变形耦合效应的分析结果是合理的。     

链子崖T_（11）—T_（12）缝段危岩体开裂变形机制

文章全面描述了链子崖Ｔ（１１）—Ｔ（１２）缝段危岩体的开裂形变特征，探讨了危岩体形成的影响因素，如重力、煤层采空区、降雨、水库蓄水、勘探掘进和地震等，指出其破坏机理是重力主导下的不对称的压力拱与悬臂梁（板）弯矩的联合作用。危岩体可以分成具有不同稳定程度的若干块体，治理工程也应针对它们的不同特点而设计。     

可变径全圆针梁台车在TBM施工隧洞衬砌中的应用

TBM开挖隧洞,由于刀盘及刀具的限制,目前开挖完的隧洞为同一直径,为了保证后期衬砌施工中结构的强度,需要对不同的围岩类别采取不同的衬砌厚度。研究表明,采取可变径全圆针梁台车进行这方面的衬砌,具有明显的优越性。本文基于吉林引松供水工程项目,论述了可变径全圆针梁台车在TBM施工隧洞衬砌中的应用。     

改进的同名直线匹配及三维重建技术

针对已有三维直线重建算法的不足,提出了基于同名直线和点云数据的三维直线重建算法,该算法先应用单应矩阵与核线双重约束实现直线匹配,再依据共线条件方程的基本原理,经过初步确定高程值、验证与精化高程值、光束与物面交会及精化三维空间直线段等一系列过程,最终实现空间直线的三维重建.该实现过程简单易懂,并能获得较高精度的三维空间直...     

等效梁的刚度分析及应用

本文以板架为例，利用结构分析中的板单元、膜单元建立结构模型，将其计算结果与利用等效刚度梁、板单元建立的结构模型计算结果进行比较，通过分析，了解等效刚度梁在结构分析中的利弊。     

Updated bathymetric survey of Kick-'em-Jenny submarine volcano

High-resolution bathymetric data obtained in July 1996 during a survey of the Kick-'em-Jenny submarine volcano north of Grenada in the Lesser Antilles revealed changes in the structure of the volcanic edifice compared to previously available surveys. The volcano's summit, at 178 m below sea level, was found to be approximately 18 m farther from the surface than was reported by Bouysse et al. (1988) and others. No dome was observed. Instead, an open crater, surrounded by walls that dropped significantly in elevation from one side to the opposite, suggest that eruptions, earthquakes, rockfalls or explosions may have altered the structure since the last detailed survey. The deepest contour of the volcano's crater was found 106 m below the summit.     

Parametric study on offshore jacket launching

Platform structures are commonly utilized for various purposes including offshore drilling, processing and support of offshore operations. Jacket type structures are attractive in relatively shallow water regions. A jacket is a supporting structure for deck facilities stabilized by leg piles through the seabed. The size of a jacket is dependent on deck size, pile dimensions and environmental loads. In a jacket design, operational and environmental loads are very important and must be investigated intensively to secure the stability of structures during their operation life, and installation phase as well. To confirm the stability, several analyses including in-place, fatigue, dynamic, load-out, transportation, lifting, and launching are performed. As the jacket weight and dimensions become large, a launching technique is applied to install the jacket. The launching analysis needs to consider quite a number of parameters including environmental conditions, launch barge specification, ballast, trim angle, local member integrity, etc. Due to the complexity of the operation, there is not a straightforward guideline or procedure for analysis. In this paper, a general procedure for analysis with various conditions and launching criteria are discussed and investigated. The effects of parameters are closely examined by numerical modeling.