桶形基础平台海上沉放安装

桶形基础平台是世界上一种最新型的海洋平台，可广泛应用于海上油气田开发。为满足我国际油气田开发中卫星平台的结构和功能要求，桶形基础平台采用新的压载沉放方法安装，具有更高的效率和经济性。沉放过程中桶形基础平台受到水流和波浪的作用，结合模型试验对平台运动进行数值模拟分析，以了解在整个沉放过程中相应参数的变化趋势。根据桶形基础平台的特征，制定联台沉放方案，并通过压载实现平台的沉放控制。     

A review on the behavior of helical piles as a potential offshore foundation system

Abstract

Helical piles are used mainly to resist tension forces generated by uplift and overturning moments of various structures, therefore they have been suggested as a potential alternative to driven piles as offshore pile because they provide a large uplift capacity due to the anchor effect of the helix. To date no standards are available for the assessment of the use of helical piles in the offshore environment. State-of-the art installation and uplift capacity assessment is based on field onshore tests on small helical piles. The purpose of this review is to critically evaluate the current knowledge on helical piles considering uplift capacity, cyclic load, installation torque models and the parameters affecting the installation torque, to understand whether they can be considered for potential offshore applications. The paper could be of valuable interest for engineers and contractors involved in the offshore installation of piles.     

Influence of diaphragm wall installation on the numerical analysis of deep excavation

This paper presents a numerical analysis of the influence of initial stress state on the response of deep excavation supported by retaining wall. Indeed, the influence of diaphragm wall installation prior to excavation works may affect the soil response and lateral wall deflection induced by excavation process. The first part of this paper gives a short review of the numerical methods aimed to reproduce the retaining wall installation. Numerical analysis of a deep excavation in two‐dimensional and three‐dimensional conditions is then performed according to the methods previously presented. In three‐dimensional conditions, diaphragm wall installation is performed considering a sequence of panels, described by their number and length. Results of three‐dimensional calculations confirm that stress state is disturbed by wall installation, which has a sensitive effect on the ground response induced by soil excavation. It is also noted that these results are not easily reproduced in two‐dimensional conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

定点式横向声学多普勒流速剖面仪应用研究

介绍了应用定点式横向声学多普勒流速仪进行实时流量在线监测方面的比测率定研究工作。主要从设备选型、安装位置、代表流速计算、单元流速区间选择、关系率定、精度评定、测点流速分析等方面进行了分析研究。通过设备选型、安装位置、单元流速区间选择等多方面的比较分析,选择最佳方案,进行比测分析,率定出代表流速与断面平均流速的关系。重点对设备安装位置、单元流速区间的选择、流速横向分布等进行比较分析,对于其他测站的类似H-ADCP监测方案有一定的指导意义。     

我国非开挖行业现状与展望

概述了常用的各类非开挖施工技术方法及非开挖施工的主要优势;介绍了我国非开挖行业的3个发展阶段,目前的发展现状,以及存在的主要问题;对我国非开挖技术的市场前景进行了分析判断。     

水平定向钻进技术在浅层低渗透性含水层地下水开采中的试验研究

浅层低渗透性含水层埋深浅、渗透性低,难以用常规管井开采。利用水平定向钻井技术,可在含水层内长距离铺设过滤器,从而增大水井出水量。研制的贴砾过滤器,其性能经水平井试验验证满足水平井成井要求,取得了良好的试验效果。     

.NET框架下IPv6和IPv4双协议兼容的测试用例实现

在.NET框架下,利用VC＋＋编程语言开发在Windows平台上检测IPv6网络互联情况的测试用例程序,程序对IPv4同样兼容。主要介绍了适用于双协议的Socket API函数和Socket通信原理,给出在双协议下客户机/服务器通信的应用程序及实现思路,为双协议下的其它网络应用程序开发打基础。     

注册表的使用与维护

分析了WinNT服务器注册表的信息组成,介绍了注册表的结构、使用及维护方法.     

基于Windows NT下Win95无盘站的安全管理

介绍利用修改系统注册表（Registry)的一些功能项来达到在WindowsNT下Windows95无盘工作站的安全使用，提高网络的性能，减轻网络管理员的维护量。     

地震监测台网的最佳理论设置初探

本文所讨论的问题是在一个平面区域Ｄ内应如何设置地震监视台，使在该区域内任何一点发生地震，在距震源５０公里的圆周内，至少有４个地震台可监视地震情况，而且使区域Ｄ内设置的地震监视台个数最少．这里，首先对Ｄ为一有界闭区域，给出了在Ｄ内设置的地震监视台个数的下界，并且讨论了Ｄ为半径为５０的圆盘时，地震监视台的下确界以及地震台设置的设计方案．进而又讨论了当Ｄ为半径为５０ｋ公里时（ｋ＝２，３，……）时应设置地震台个数的下界．