石化工程施工技术现状与展望

改革开放以来，我国石油化工建筑安装工程的施工技术突飞猛进，已有一大批单项工程的施工技术水平赶上或超过了发达国家，其中基坑支护、高塔设备制造吊装、大型设备运输、强夯处理抛石填海地基等施工技术成就尤其突出，该文对此予以综述，指出施工企业在市场竞争中加强现代企业管理和提高工程质量的基本途径。     

库尔勒-鄯善输油管道工程中施工新技术的应用

库尔勒—鄯善输油管道是国内第一次使用 ＡＰＩ ５ＬＸ６５管材的长距离输油管道。这种管材强度高、焊接工艺复杂。本文归纳了该管道工程的施工特点,并介绍了在焊接工艺、防腐结构等方面采用的新技术、新工艺。     

汤浦水库引水隧洞工程Ⅰ标段隧洞洞挖爆破设计与施工概述

简要介绍了浙江省汤浦水库输水隧洞工程洞挖爆破的设计、施工及实施效果.     

全断面掘进机(TBM)刀盘总推进力的分析计算

探讨了在不同的地质条件下TBM刀盘总推进力的设计计算方法,有利于优化TBM的结构参数和总装机功率,提高TBM适应不同地质条件的能力,并以ROBBINS(美)公司MB264-311型TBM为例进行了模拟计算,证明该计算方法正确有效。     

Research on Combined Construction Technology for Cross-Subway Tunnels in Underground Spaces

Given the increasingly notable segmentation of underground space by existing subway tunnels, it is difficult to effectively and adequately develop and utilize underground space in busy parts of a city. This study presents a combined construction technology that has been developed for use in underground spaces; it includes a deformation buffer layer, a special grouting technique, jump excavation by compartment, back-pressure portal frame technology, a reinforcement technique, and the technology of a steel portioning drum or plate. These technologies have been successfully used in practical engineering. The combined construction technology presented in this paper provides a new method of solving key technical problems in underground spaces in effectively used cross-subway tunnels. As this technology has achieved significant economic and social benefits, it has valuable future applications.     

A deep learning-based method for detecting non-certified work on construction sites

The construction industry is a high hazard industry. Accidents frequently occur, and part of them are closely relate to workers who are not certified to carry out specific work. Although workers without a trade certificate are restricted entry to construction sites, few ad-hoc approaches have been commonly employed to check if a worker is carrying out the work for which they are certificated. This paper proposes a novel framework to check whether a site worker is working within the constraints of their certification. Our framework comprises key video clips extraction, trade recognition and worker competency evaluation. Trade recognition is a new proposed method through analyzing the dynamic spatiotemporal relevance between workers and non-worker objects. We also improved the identification results by analyzing, comparing, and matching multiple face images of each worker obtained from videos. The experimental results demonstrate the reliability and accuracy of our deep learning-based method to detect workers who are carrying out work for which they are not certified to facilitate safety inspection and supervision.     

Expansive Workflows: Downstream Coordination in the Design of Sporting Facilities

Heightening user experience is a key aim for global architecture practice Populous, specialists in designing sports and entertainment venues. Jonathan Mallie , lead principal in their New York office, outlines their working process. The digital realm plays an important part: from building information modelling, to immersive technologies that imaginatively engage communities in the creative process. But such large-scale, time-sensitive projects as the Jacksonville Jaguars American football facility in Florida would be impossible without also establishing a team spirit among all those involved.     

编码协作系统准循环重复累积码的联合设计与性能分析

重复累积(RA)码是一种特殊结构的低密度奇偶校验(LDPC)码,不仅具有LDPC码的优点,还能实现差分编码。针对LDPC编码协作系统编码复杂度高、时延长的问题,该文引入准循环RA(QC-RA)码,推导出信源节点和中继节点采用的QC-RA码对应的联合校验矩阵,基于公差构造方法设计该联合校验矩阵,并证明该方法设计的联合校验矩阵不存在围长为girth-4, girth-6的短环。理论分析和仿真结果表明,同等条件下该系统比相应点对点系统具有更优异的误码率性能。仿真结果同时表明,与采用一般构造QC-RA码或基于Z型构造QC-RA码相比,采用基于公差构造的联合设计QC-RA码的多信源多中继协作均可获得更高的编码增益。     

Developing Structural Integrated Stressor–Stress Models for Clients’ and Contractors’ Cost Engineers

Estimation is not a purely scientific task. It requires cost engineers equipped with a wide knowledge of construction and a professional ability to make judgments. However, stress will deaden their use of knowledge and influence their professional judgment in estimating. In the construction industry, cost engineers can generally be divided into two main groups: clients’ cost engineers in consultant firms or in a development company who serve clients; and contractors’ cost engineers in construction companies working for the contractors. This study investigates the causal relationships between the stressors and stress of clients’ and contractors’ cost engineers. Two stressor–stress integrated models were developed for these two cost engineer groups by using the structural equation model. The findings revealed some stressors that affected both clients’ and contractors’ cost engineers: (1) poor environment, role conflict and work underload affect their stress positively; (2) social support and Type A behavior affect their stress negatively; and (3) work underload induces stress via the role conflict among cost engineers, their supervisors, and the organization. On the other hand, some deviations between these two groups of cost engineers also occur: (1) social support acts as a source of stressors of clients’ cost engineers; (2) a private life stressor only affects the stress of contractors’ cost engineers; and (3) a closed interactive looping relationship among role conflict, Type A behavior, and work underload affects contractors’ cost engineers. Based on the results of this study, some recommendations are suggested to manage cost engineers’ stress well.     

Emergency Contracting Strategies for Federal Projects

During the past decade, government agencies have struggled to adequately respond to emergency events that require labor, materials, equipment, and services provided by construction contractors. In fact, the criticism directed at government agencies during their response to, and recovery after, recent events is a testament to the insufficient contracting strategies that were implemented. Countless media headlines highlighted the fragmented approach used to hire contractors expeditiously, and several agencies were criticized for their inconsistent contracting methods. As a result, a study was initiated to investigate the differences between normal federal contracting procedures, as outlined in the Federal Acquisition Regulation (FAR), and emergency acquisition procedures that are permitted by the FAR. The study found six examples of waivers to the usual regulations or expedited contracting techniques permitted by the FAR. Furthermore, the study highlighted five emergency contract strategies that are available to the Navy (as one example of a government agency with contracting authority) and may be available to other governmental contracting authorities as well. Consequently, the purpose of this paper is to identify emergency contract strategies that can be used by government agencies and to outline the criteria that must be met to use each strategy.