超声波CT成像技术及其在大型桥梁基桩无损检测中的应用

在大型桥梁基桩的超声波检测中,为了准确确定异常部位的尺寸,将CT成像技术引入到超声波检测中,实际工程应用结果表明,这种技术具有分辨率高,缺陷定位准确,检测结果直观,图象清晰等特点。     

Magnetic resonance imaging of atherosclerotic lesion with new devised animal surface coil

The ability of dynamic contrast enhanced magnetic resonance imaging(DCE MRI) with a new devised animal surface coil was analyzed in identifying atherosclerotic plaques in the rabbit medium-sized iliac artery(IA).Then a comparative analysis of multi-detector computed tomography(MDCT) and DCE MRI was done in discerning morphology and components of 80 atherosclerotic plaques identified by histopathology.It shows that the DCE MRI may be an emerging noninvasive and economic way to characterize atherosclerotic plaques at present.What's more, a new devised animal surface coil would further improve the signal-to-noise ratio(SNR) and the quality of imaging.However, CT angiography(CTA) may be better than MR angiography(MRA) in detecting vessel stenosis.     

盘海高速公路辽河特大桥基桩超声波无破损检测方法简介

主要介绍了超声波检测的原理，以及盘海高速公路辽河特大桥利用超声波检测基桩的情况。     

A simplified analysis method for the lateral deformation of braced excavations

Pile-anchor retaining structure is widely used in foundation pit engineering and side slope engineering in many countries. In contrast to strut, pile-anchor retaining structure has its typical features and advantages. It does not occupy the internal space of the foundation pit, and the project cost is much lower. Accurate prediction of the lateral displacement of the retaining structure is very important in the design stage. A simplified analysis method and several calculation assumptions of the lateral deformation of pile-anchor retaining structures are set up according to the engineering features. The expression function of lateral displacement versus depth is solved by means of a fitted function and the quasi-elastic summation method. The parameters are obtained through the stiffness equation of the anchors and the principle of minimum potential energy. The analytical evaluation of the lateral deformation curve is then completed, whose applicability is proved through practical engineering.     

Preface

It has been 90 years since Hermann Kemper first proposed the concept and principle of the electromagnetic suspension (EMS) technology in 1922.To date,electromagnetic suspension technologies have found wide range of applications in transportation,magnetic bearings,space technology,etc. In last decades,Germany took the lead in the EMS maglev technology and Japan set a world record in the maglev train speed of 558km/h with its unique superconducting EDS (electrodynamic suspension) maglev technology.China initiated the research of EMS technology in the last 1980's,and constructed the first and only commercialized maglev train line in Shanghai in 2002.     

Segmentation of haustral folds and polyps on haustral folds in CT colonography using complementary geodesic distance transformation

Computer-aided detection （CAD） for CT colonography refers to a scheme that automatically detects polyps in CT images of colon. Current CAD schemes already have a relatively high sensitivity and a low false positive rate. However, misdiagnosis and missed diagnosis are still common to happen, mainly due to the existence of haustral folds （HFs）. An innovative idea of segmenting semilunar HFs from the smooth colonic wall and then using different methods to detect polyps on HFs and those on the smooth colonic wall is proposed in this paper to reduce the false positives and false negatives caused by HFs. For the polyps on HFs, a novel segmentation method is specially developed based on complementary geodesic distance transformation （CGDT）. The proposed method is tested on four different models and real CT data, The property of CGDT is proved and our method turns out to be effective for HF segmentation and polyp segmentation. The encouraging experimental results primarily show the feasibility of the proposed method and its potential to improve the detection performance of CAD schemes.     

桥梁无损检测技术的提高方法

分析和研究某地桥梁桩基检测工程,结合超声波检测技术应用原理、具体检测步骤、发展前景等方面进行阐述,最终分析得出在检测桥梁缺陷中,应用无损检测技术的实用性和可行性,并提出提高无损检测技术水平的措施,希望可以更加准确的判断出桥梁缺陷部位。     

An Intelligent Response Surface Methodology for Modeling of Domain Level Constraints

An effective modeling method of domain level constraints in the constraint network for concurrent engineering （CE） was developed. The domain level constraints were analyzed and the framework of modeling of domain level constraints based on simulation and approximate technology was given. An intelligent response surface methodology （IRSM） was proposed, in which artificial intelligence technologies are introduced into the optimization process. The design of crank and connecting rod in the V6 engine as example was given to show the validity of the modeling method.     

Novel Asynchronous Wrapper and Its Application to GALS Systems

An asynchronous wrapper with novel handshake circuits for data communication in globally asynchronous locally synchronous （GALS） systems is proposed. The handshake circuits include two communication ports and a local clock generator. Two approaches for the implementation of communication ports are presented, one with pure standard cells and the others with Mttller-C elements. The detailed design methodology for GALS systems is given and the circuits are validated with VHDL and circuits simulation in standard CMOS technology.     

Synthetically Evaluation System for Multi-source Image Fusion and Experimental Analysis

Introduction The image fusion technology produces a singleimage from a set of input images. The fused imageshould have more complete information which ismore useful for human or machine perception.With the merits of high degree of system explo-ration, automation, availability, reliability, capa-bility and low cost, it boasts broad application per-spective in many fields such as computer vision,automatic object detection, image processing, par-allel and distributed processing, robotics and re-m…     

混凝土在路桥桩基施工中的作用及技术

路桥桩基混凝土施工中,为了保障灌注桩混凝土的质量,必须加强对准备工作及施工工艺的重视.通过对混凝土及其施工质量要求进行分析,探讨了混凝土在路桥桩基施工中的配合比、泵送等,并阐述了路桥桩基施工技术.     

混凝土在路桥桩基施工中的作用及技术

路桥桩基混凝土施工中，为了保障灌注桩混凝土的质量，必须加强对准备工作及施工工艺的重视。通过对混凝土及其施工质量要求进行分析，探讨了混凝土在路桥桩基施工中的配合比、泵送等，并阐述了路桥桩基施工技术。     

辽河大桥大直径深水超长桩基础桩底压浆的关键技术

辽河大桥39#主塔桩基础为大直径深水超长群桩基础,对全部39根桩进行了桩底后压浆,有效地提高了桩基承载力和整体刚度,减少了基础的不均匀沉降.重点介绍大规模群桩基础通过桩底压浆提高承载力的机理、压浆工艺及压浆效果.     

小桥桩基础的钻孔灌注桩施工控制

小桥基础的钻孔灌注桩技术是通过设置一个一定直径的钻井孔,在其内放置钢筋笼、灌注混凝土而做成的桩。这种方法在建筑物的施工中使用范围很广,可以用于各种土层,甚至可以进入基岩层进行施工,这是其他施工方法做不到的。对这种施工技术进行了详细介绍。     

京沪高铁跨西气东输管道刚构桥设计与施工技术

针对京沪高速铁路跨西气东输管道技术含量高、工期任务紧、安全隐患大的特点,考虑到地基承载力相对较低及铁路跨管道施工高危险性因素,决定采用桩基础加承台刚构桥结构形式跨越管道。桩基施工采用挖孔桩,岩石迫裂采用钻孔灌膨胀剂等技术。从该桥设计要点、施工技术、安全防护措施等方面进行了介绍,为今后类似工程提供参考。     

砼管桩基础施工技术在东平大桥中的应用

以佛山东平大桥龙门轨道管桩基础和拱肋拼装支架管桩基础施工为例,介绍预应力砼管桩在不良地层中作为临时施工基础的应用以及其施工工艺技术等.     

地铁隧道近距离穿越桥桩关键施工技术

地铁隧道邻近结构物,施工难度大、风险高,是地铁施工中的技术难题.大连地铁1号线黑石礁车站风道与轻轨桥桩之间最近距离仅为1.9 m,隧道开挖对桥桩影响较大.施工期间,按照一定间距在风道与桥桩之间采用钢管隔离桩措施,在水平方向上起到了变形阻断作用,有效地保证了隧道近距离穿越桥桩施工的安全.     

某桥邻桩施工临界时间控制

在影响群桩基础施工质量的因素中,相邻桩施工时间间隔是一个关键性因素。它不仅仅影响桩基础的施工质量,而且影响桩基础的施工进度,进而影响工程项目的整体进度。作者通过分析某桥相邻桩施工临界时间间隔,通过声波检测方法验证了相邻桩基在临界时间间隔施工情况下桩基混凝土质量,并分析了影响临界时间相关因素。达到了尽量缩短桩基础施工工期、提高整体工程进度的目的。     

邹县电厂深基坑开挖支护及既有铁路线跨越技术

结合邹县电厂四期工程0号卸煤沟及转运站工程,介绍了在该工程深基坑开挖中使用的预制桩、钻孔灌注桩锚杆支护技术及架设的铁路线路跨越基坑施工便桥,并应用ANSYS软件对12m基坑的施工过程进行了模拟,结果显示此模拟技术能较好反映实际开挖过程,对同类工程有借鉴意义。     

桩土复合地基技术的发展与研究现状

桩土复合地基技术在软土地基处理工程中应用广泛。介绍了桩土复合地基的概念、分类及桩体的主要作用,简要回顾了桩土复合地基的发展历程,指出研究中存在的难点问题,并结合桩土复合地基研究中通常采用的试验、理论、数值模拟三种研究方法,分析了当前研究中存在的不足,对桩土复合地基技术未来的发展提出几点建议。