某复杂岩溶地区桩成孔工艺概述

本文对某复杂岩溶地区成孔工艺进行了分析和阐述,为类似工程提供了较好的施工经验.     

论“排放权交易”之中国构建

气候变化是当今世界的热点问题。中国应及早采取更加有效的节能减排措施。对＂排放权交易＂的基本理论和国际、国外、国内相关情况进行了考察;重点对中国构建＂排放权交易＂制度的必要性、紧迫性、可行性及不利因素进行了具体阐述;对中国＂排放权交易＂的基本要素作了初步设想。     

大直径挖孔桩在高层建筑中的应用

本文介绍了高层办公楼选择大直径挖孔扩底桩基础,具有受力明确,经济易行,质量可靠的优点,在具有较好持力层地质条件下选用此桩是适宜的.     

油桶保安盖锁紧器夹紧块的加工及夹具的设计

本文介绍了油桶保安盖锁紧器夹紧块的加工工艺及加工所用夹具的设计。     

双柱式钻孔灌注桩桥盖梁荷载内力计算

盖梁作为桥梁重要的组成部分,其主要作用是支撑上部结构的荷载作用,进而将这部分荷载作用传递到桥墩。对双柱式钻孔灌注桩桥梁盖梁进行内力计算。     

Analytical model of vertical vibrations in piles for different tip boundary conditions: parametric study and applications

In this paper,a model named fictitious soil pile was introduced to solve the boundary coupled problem at the pile tip.In the model,the soil column between pile tip and bedrock was treated as a fictitious pile,which has the same properties as the local soil.The tip of the fictitious soil pile was assumed to rest on a rigid rock and no tip movement was allowed.In combination with the plane strain theory,the analytical solutions of vertical vibration response of piles in a frequency domain and the corresponding semi-analytical solutions in a time domain were obtained using the Laplace transforms and inverse Fourier transforms.A parametric study of pile response at the pile tip and head showed that the thickness and layering of the stratum between pile tip and bedrock have a significant influence on the complex impedances.Finally,two applications of the analytical model were presented.One is to identify the defects of the pile shaft,in which the proposed model was proved to be accurate to identify the location as well as the length of pile defects.Another application of the model is to identify the sediment thickness under the pile tip.The results showed that the sediment can lead to the decrease of the pile stiffness and increase of the damping,especially when the pile is under a low frequency load.     

Analytical model of vertical vibrations in piles for different tip boundary conditions: parametric study and applicationsx

In this paper,a model named fictitious soil pile was introduced to solve the boundary coupled problem at the pile tip.In the model,the soil column between pile tip and bedrock was treated as a fictitious pile,which has the same properties as the local soil.The tip of the fictitious soil pile was assumed to rest on a rigid rock and no tip movement was allowed.In combination with the plane strain theory,the analytical solutions of vertical vibration response of piles in a frequency domain and the corresponding semi-analytical solutions in a time domain were obtained using the Laplace transforms and inverse Fourier transforms.A parametric study of pile response at the pile tip and head showed that the thickness and layering of the stratum between pile tip and bedrock have a significant influence on the complex impedances.Finally,two applications of the analytical model were presented.One is to identify the defects of the pile shaft,in which the proposed model was proved to be accurate to identify the location as well as the length of pile defects.Another application of the model is to identify the sediment thickness under the pile tip.The results showed that the sediment can lead to the decrease of the pile stiffness and increase of the damping,especially when the pile is under a low frequency load.     

圆装袖不同袖势结构制图的探讨

袖势是由袖窿深、袖山高、袖肥及袖山曲线确定的。文章通过对圆装袖不同袖势的变化因素进行分析,以期探讨袖势变化中如何合理设置其结构,使服装达到实用、美观、舒适的目的。     

《说文解字》中反映出的服饰文化 --《说文》汉字民俗文化溯源研究之五

中国是世界上最早植桑、养蚕、缫丝的国家,中国古代服饰文化具有很强的等级性和礼仪性.<说文解字>中的部、革部、糸部、衣部、履部汉字及相关字群字义反映了中国古代服饰文化的演变进程及其鲜明特点.     

空间钢构架混凝土承台的非线性有限元分析

基于ABAQUS大型有限元分析软件,建立了桩基厚承台非线性有限元分析模型.运用所建立的模型,对5个空间钢构架混凝土承台进行了非线性有限元分析,计算值与试验值吻合得较好,表明所建立的有限元计算模型可较好地模拟空间钢构架混凝土承台的性能;分析了空间钢构架混凝土承台内部完整的力流分布,探讨了空间钢构架混凝土承台的受力机理,为空间钢构架混凝土承台传力模型的建立提供了理论计算依据.在理论分析和以往研究的基础上,提出了空间钢构架混凝土承台的桁架模型.