车站共墙基坑拆撑回筑结构体系受力变形特性

深基坑内支撑拆除及坑内结构回筑会改变深基坑原来支护体系的受力平衡状态,失衡荷载会引起围护结构内力重分布,对其稳定性造成影响。共墙基坑群内支撑拆除过程荷载变化机理比单独基坑更为复杂,其安全控制更为严格。本文基于前海站共墙基坑工程,通过对基坑拆撑回筑全过程数值模拟,分析内支撑拆除过程中结构受力及位移的变化规律。结果表明:1)拆撑会改变围护结构的内力状态及位移变形,且共墙侧与非共墙侧的变化规律存在显著差异:共墙侧地连墙弯矩极值与极值位置均发生变化,围护结构位移随拆撑逐渐减小,非共墙侧弯矩分布规律变化较小,围护结构位移逐渐增大。2)支撑拆除后相邻内支撑轴力会急剧上升,其中第二道、第四道轴力分别增加了30.4%、46.2%,增设临时钢支撑能有效减少轴力增量;3)回筑过程中主体结构两侧外墙位移变形较小,最大位移分别为10.57和5.74 mm;4)拆撑回筑过程地表沉降共增长了18.9%。

悬臂支护基坑施工对邻近地铁隧道结构的影响分析

本文是针对无锡某商业街区悬臂支护基坑开挖及回筑施工时对邻近的已建地铁隧道(未运营)的结构内力及变形的影响分析。采用ABAQUS软件对各工况进行了数值模拟,得到了基坑开挖及回筑过程中隧道结构所受影响的分析结果。为该基坑施工对邻近地铁隧道结构影响的安全性评估工作提供了参考意见。

Settlement Prediction for Buildings Surrounding Foundation Pits Based on a Stationary Auto-regression Model

To ensure the safety of buildings surrounding foundation pits, a study was made on a settlement monitoring and trend prediction method. A statistical testing method for analyzing the stability of a settlement monitoring datum has been discussed. According to a comprehensive survey, data of 16 stages at operating control point, were verified by a standard t test to determine the stability of the operating control point. A stationary auto-regression model, AR(p), used for the observation point settlement prediction has been investigated. Given the 16 stages of the settlement data at an observation point, the applicability of this model was analyzed. Settlement of last four stages was predicted using the stationary auto-regression model AR (1); the maximum difference between predicted and measured values was 0.6 mm, indicating good prediction results of the model. Hence, this model can be applied to settlement predictions for buildings surrounding foundation pits.

Unified Model of Purification Units in Hydrogen Networks

Purification processes are widely used in hydrogen networks of refineries to increase hydrogen reuse. In refineries, hydrogen purification techniques include hydrocarbon, hydrogen sulfide and CO removal units. In addition, light hydrocarbon recovery from the hydrogen source streams can also result in hydrogen purification. In order to simplify the superstructure and mathematical model of hydrogen network integration, the models of different purification processes are unified in this paper, including mass balance and the expressions for hydrogen recovery and impurity removal ratios, which are given for all the purification units in refineries. Based on the proposed unified model, a superstructure of hydrogen networks with purification processes is constructed.

Recycling Plastics for Economical Housing

Abstract： The search for ＂new materials＂ to manufacture building elements for economical housing is the aim of this work. These materials are the following recycled plastics： Low-density polyethylene （LDPE）, recycled out of discarded soft drink packs： Polyethylene-terephthalate （PET）, recycled out of discarded soft drink bottles; and several plastics, from the printed films used like packages of candies （remainder of production plant by faults in the thickness of the films or in the inked process of themt. These conveniently grounded plastics were taken as ＂arids＂ to be mixed with Normal Portland cement, replacing heavy sand and gravel habitually used in these mixtures. These materials are used in constructive elements such as bricks, blocks and plates for economical houses closures or traditional construction. The developed constructive elements offer high thermal insulation, so they can be used in closures with a smaller thickness than conventional bricks and blocks. Besides, they have a lower specific weight than these traditiunal constructive elements. Recycling means lowering costs, making part of the environment contaminating waste useful and providing the unemployed and/or unqualified work force with jobs through uncomplicated technologies. Therefore, this recycling technology has an economic as well as an ecological purpose.

A Case Study for End of Life Reuse and Recycling Survey Methodologies： The Hollentalanger Cottage

Up to now, reuse and recycling of existing buildings have not been examined widely. This paper discusses the theories, methods and practicalities of buildings＇ end of life with a main focus on planning and managing reuse and recycling of existing buildings. Our aim is the realistic modelling of theoretical scenarios for end of life based on a case study. The methods of building survey, material classification and documentation for reuse, recycling and disposal of existing constructions are presented. Investigations and calculations were done on an existing cottage in the Alps. The ecologically most beneficial disposal phase of the old wooden hut is our main objective. Critical questions arise from the quality of the material and how it can be extracted, separated and balanced in an appropriate way. A systematic survey of the building by inspection of constructions and materials in iterative steps allows a detailed material balance with condition and property information. This information is crucial for scenarios and material flow analysis of demolished and rebuilt building in environmental system analysis. For future planning, the reuse and recycling of existing buildings should be integrated quite early in the planning process so that we can use the materials in the best way.

The Ideal Usage of Sustainable Materials and Local Resources of the Interior Space Design in Jordan

Buildings generate a large amount of waste throughout their life cycles, from construction and building operations to demolition. The amount of waste leaving the properly can be reduced, however, through responsible procurement choices, as well as by implementing comprehensive recycling programs throughout the construction, operation, and demolition phases. Consideration for materials and resources focuses on the health and productivity consequences of material selections for building occupants, plus the long term social, economic, and environmental impacts of materials used in the design and construction of the building. Green building addresses two kinds of problems related to materials and resources： waste management and life-cycle impacts. This issue has been discussed by many professionals and researchers and it seems this problem is more likely existed in not developing countries comparing with developing countries. The lack of selecting the right materials, have not been well taken into the consideration. Researchers have developed a number of assumptions that helps to resolve the research problems, which includes the application of the green material and resource in the Jordauian interior designs to provide a healthy environment to the interior spaces. Therefore, the paper aims to search for the possibilities of proposing some indicators using sustainable material and resource in the of internal Jordanian spaces. The theoretical part goes through a brief study to definition of sustainable material and resource in Jordan, and its uses in all the elements of internal and emphasis about the traditional symbols to preserve the identity of Jordan, then we going through the uses of the material and resources by analyses examples of the green interior spaces in Jordan.

深基坑工程内衬结构替代换撑支护的技术分析

在深基坑工程中,因支撑竖向间距较大,回筑阶段一般考虑换撑。介绍了利用增量法原理,结合实际工程,通过对换撑、不考虑内衬直接拆撑和内衬结构替代换撑三种方案进行计算,并与基坑监测相对比,表明内衬结构替代换撑合理可行,有较高的推广应用价值。

杭州地铁1号线闸弄口站深基坑换撑方案优化设计

结合杭州地铁1号线闸弄口站深基坑设计与施工实际情况,根据深基坑施工监测数据,并反馈分析,对换撑方案进行优化。在确保基坑回筑过程施工安全和内部结构质量的条件下,取消换撑支撑,加快了施工进度,提高了工程质量,取得了明显的经济效益。

Liver-targeting macromolecular MRI contrast agents

Macromolecular ligands with liver-targeting group (pyridoxamine, PM) PHEA-DTPA-PM and PAEA-DTPA-PM were prepared by the incorporation of different amount of diethylenetria-minepentaacetic acid monopyridoxamine group (DTPA-PM) into poly-α, β-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA) and poly-α, β-[N-(2-aminoethyl)-L-aspartamide] (PAEA). The macromolecular ligands thus obtained were further complexed with gadolinium chloride to give macromolecular MRI contrast agents with different Gd(III) contents. These macromolecular ligands and their gadolinium complexes were characterized by1H NMR, IR, UV and elementary analysis. Relaxivity studies showed that these polyaspartamide gadolinium complexes possess higher relaxation effectiveness than that of the clinically used Gd-DTPA. Magnetic resonance imaging of the liver in rats and experimental data of biodistribution in mice indicate that these macromolecular MRI contrast agents containing pyridoxamine exhibit liver-targeting property.

Where are demolition wastes going:reflection and analysis of the February 6,2023 earthquake disaster in Turkey

On 6 February 2023 at 09.17 BST,an earthquake measuring 7.8 on the Richter scale struck the southern border of Turkey near Syria,causing massive casualties and building damage.Badly damaged buildings need to be demolished,bringing a large amount of demolition waste,which,if not properly disposed of,can be a burden on the environment.In this study,damage to buildings in the quake-hit areas of Turkey is investigated,including reinforced structures and masonry structures.Based on this,the amount of demolition waste produced and the proportion of waste components are estimated roughly.Ultimately,the paper puts forward the strategy of recycling demolition waste after the earthquake and the application scenario planning of recycled products.Conclusively,the amount of demolition waste generated after the earthquake ranges from 450 to 920 million tons,providing new ideas for post-disaster reconstruction work.Besides,post-disaster waste management,safe demolition and environmentally friendly disposal and recycling technologies for demolition and construction wastes will bring good economic and environmental benefits,help the reconstruction of disaster areas,and provide a model for the resource utilization of construction and demolition waste worldwide.

Axi-symmetric Active Earth Pressure for Layered Backfills Obtained by the Slip Line Method

The axi-symmetric active earth pressure for layered backfills was investigated using the slip line method. Due to different soil properties, the interfaces of the soil layers were considered as discontinuity surface. Accordingly, the change of the major principal direction was obtained and a new computation scheme was proposed to deal with the discontinuity in the calculation, finally the slip line method was extended to layered backfills. Results indicate that, the major principal direction, as well as the earth pressure, has a finite jump on passing the soil interfaces. The magnitude of the jump depends on the soil properties mainly. Generally, the active earth pressure when a strong layer is overlying a weak layer is much larger than that when the weak layer is lying on the strong layer. The present solution can be reduced to plane strain case and it has been compared with Rankine's and Coulomb's results, and a good agreement is observed.

Value-added recycling of sludge and sludge ash into low-carbon construction materials:current status and perspectives

Sludge as the by-product of wastewater treatment usually accumulates toxic substances that require specific treatment before disposal.With the increase of sludge production,the safe and economic treatment of sludge has become a global issue.Construction filed provides a solution for consuming huge volumes of sludge and sludge ash owing to the similar chemical composition with cementitious materials.This paper critically reviewed the current status of recycling sludge and sludge ash into low-carbon construction materials and highlighted the future perspectives of sludge-derived construction materials.Furthermore,the immobilization mechanisms of heavy metals in sludge-derived construction materials were elaborated to promote the actualization of sustainable management of sludge and sludge ash.