Integration of three dimensional discontinuous deformation analysis (DDA) with binocular photogrammetry for stability analysis of tunnels in blocky rockmass

This paper demonstrates and evaluates an integrated system coupling 3-dimensional binocular photogrammetry and discontinuous deformation analysis (DDA) for stability analysis of tunnels in blocky rockmass. 3D DDA is an effective numerical method for discontinuous and large displacement problems. In stability analysis of rockmass, especially for tunnels, one of the primary bottlenecks in 3D DDA is generating discontinuous models. For tunnel constructions requiring small interval time for blasting, traditional geotechnical data collection approaches such as hand-mapping and geologic compass are always lacking in efficiency and accuracy. 3D photogrammetry is an economical and efficient method for collecting geometric features and surface data. An integrated system connecting geometrical data acquisition and discontinuous numerical analysis automatically, is valid for improving safety in tunnel construction. This system includes photogrammetry module, modeling module and analysis module. In the photogrammetry module, binocular photogrammetry devices and image reconstruction technique are implemented for geometric data of rockmass. Then location, dip direction and dip angle of joints as well as other geometric information of tunnels are input into the modeling module to generate 3-dimensional discontinuous models. The analysis module using 3-dimensional DDA to evaluate the stability of the surrounding rock in tunnels. The integrated system is implemented in an engineering instance, Suocaopo Tunnel in Guizhou, China.     

三维电极法处理染料废水的研究

归纳了染料废水的各类处理方法,从反应器结构、电极板材料、粒子电极、操作条件等方面总结了三维电极法处理染料废水的研究发展方向及存在的问题,并对其未来进行了展望,以推进和发展该方法的应用。     

三维超声层析成像法在高速公路典型病害成因挖掘中的关键技术

结合三维超声层析成像技术在某公路路面质量检测中的应用,介绍了超声成像技术的基本使用方法及特点。通过采用该方法对路面缺陷进行检测,查清了结构内部的有害脱空的尺寸大小及空间位置,为施工单位的修补提供了科学的参考资料。三维超声层析成像技术具有简便、直观、信息量大等优点,在公路工程中有着广阔的应用前景。     

Photocatalytic cement-based materials: Comparison of nitrogen oxides and toluene removal potentials and evaluation of self-cleaning performance

Using cement-based building materials as a matrix for nano-photocatalysts is an important development for the large scale application of photocatalytic technologies. Air pollution mitigation and self-cleaning surface are two major applications of photocatalytic building materials. In this study, a comparison was made to evaluate the performance of TiO₂ modified concrete surface layers for NO_x and VOC degradation. The self-cleaning performance of TiO₂ modified self-compacting mortars (SCM) developed for decorative applications was also evaluated. The results show that the photocatalytic conversion of toluene by the TiO₂ modified surface layer was not detected, although NO_x could be effectively removed under the same conditions. The presence of toluene did not influence the NO_x removal process. TiO₂ modified SCM were found to be effective in the discoloration of rhodamine B under UV and strong halogen light irradiation. The level of adsorption of the air contaminants onto the active sites of the cement-TiO₂ composite was identified to be the key factor determining the subsequent photocatalytic efficiency.     

A support tool incorporating a districtdisaster mitigation performance evaluation method for the examination of improvement plans in built-up areas

Approximately 20,000 ha of densely built-up areas still remain in Japan. However, the advance of improvements in these areas has been very slow. Thus, making draft improvement plans through citizen–administration partnerships is indispensable to promote improvements. The planning support tool proposed in this study supports a consensus-building process during the creation of draft improvement plans. We develop a disaster mitigation performance evaluation method (DMPEM) for built-up areas at the district level and incorporate this method into a disaster mitigation support Web-GIS. However, DMPEM requires lengthy calculation time because it uses the probabilistic Monte Carlo computation method. Using this tool in real- time planning is therefore difficult. In this study, we first develop a system that reduces the calculation time required by DMPEM. Second, the support tool is used to make draft plans through citizen–administration partnerships in districts where residents are conducting various disaster mitigation activities. Finally, we investigate the usefulness of the tool for consensus building through the promotion of lively discussions among residents and clarify the issues associated with practical use of the tool.     

松散承压含水层地区深基坑降水三维渗流与地面沉降耦合模型

以上海环球金融中心基坑降水为例,根据基坑降水过程中有效应力和孔隙水压力的转化关系,建立了基坑降水与地面沉降的耦合模型,并采用有限差分数值模拟方法,模拟了在多层含水层复合存在、含水层最深底板埋深达145 m、基坑周围挡水连续墙埋深达34 m、抽水井埋深达55 m、抽水井过滤器埋深为34～55 m,单井抽水量为1420 m3/d的8口抽水井联合降水情况下,基坑中心下伏第Ⅰ承压含水层上部降压段水位降至埋深26 m时的地下水复杂流动状态及其地面沉降特征。经后续工程验证,该结果正确、可靠,该理论用于模拟预测此类地区深基坑降水引起的地下水流场变化及其地面沉降具有较高的可信度。     

空间框架梁柱节点伪静力试验研究的实现

设计了一种空间框架梁柱节点伪静力加载试验系统，具有如下特点：采用梁端主动加载模式，柱端约束装置采用空间球型支座，梁端约束装置采用自主研发的套箍式球铰支座，在双向加载过程中不产生附加约束；易于采用各梁端作动器连通的同步加载规则，同时适用于伺服与非伺服加载模式。基于能量原理，将空间梁柱节点多梁端复杂滞回关系转化为等效柱端水平力-水平位移滞回关系，以更为合理地评价节点整体抗震性能。多组节点的验证性试验表明，该系统性能良好，适用于空间梁柱节点抗震性能试验研究。     

多热源多环空间热网水力工况模拟与分析方法

提出了基于空间管网平差的水力工况模拟与分析方法，应用图论理论描述了空间管网的拓扑结构，分别阐述了多热源多环热网热用户或热源无流量调节装置和有流量调节装置时的计算方法。该方法既可用于正常水力工况的模拟与分析，也可用于故障工况。     

三维岩样单轴压缩自由面剪应变率及位移分布数值模拟

以往FLAC对岩样变形、破坏进行数值模拟主要是针对平面应变二维问题,离三维岩样单轴压缩的试验条件还有不少差距。因此,本文采用FLAC-3D研究了三维岩样在单轴压缩及强烈端面约束条件下,自由面的剪切应变率、离面位移及面内位移的分布及演变规律,研究了自由面垂直对称轴上定点位移随时步的演变规律。在应力峰值之前及之后,本构模型分别取为线弹性及莫尔–库仑剪破坏与拉破坏复合的应变软化模型。计算表明:在应力–时步曲线的应力峰值之前,自由面上的剪切应变率由均匀向不均匀分布转变;在应变软化阶段,试样的变形由对称性向非对称性转变。通过分析各个自由面的剪切带图案发现,在试样内部形成了两个空间剪切带,其中一个更占优势。在试样变形的对称性丧失之前,三维离面及面内位移曲面是光滑的、平坦的;在对称性丧失之后,三维曲面已变得凹凸不平了。在剪切带的位置,面内位移有显著的改变。自由面垂直对称轴上的离面位移在应力–时步曲线应力峰值之前发生了分离,而水平及垂直位移–时步曲线转折于应力峰值稍后或应变软化阶段。从离面位移易于识别出试样破坏的前兆。此外,在应变软化阶段,随着时步的增加,还观测到了离面位移的三种不同的变化规律:基本保持不变、增加及降低(反弹)。     

论中国区域性土的分布和岩土性质的形成

广阔的中国大地上分布着各种具有地区特点的“区域性土”:北部的黄土、南部的红土、中部的老粘土以及东南近海的海洋软土(包括沿海的软土)。它们和一般粘性土的工程特性不同,故而人们有时称之为“特殊土”。笔者曾分别对它们的工程特性和基本性质进行过研究。本文对这些“区域性土”的物理力学、物理化学和微观分析的测试成果作了系统归纳,并对这些“区域性土”的分布规律和工程特性的形成进行了综合研究。研究表明我国“区域性土”地理分布和独特的工程特性的形成,完全取决于我国的气候条件和地理地质环境。     

有限元上限分析网格自适应方法及其工程应用

网格离散误差是有限元上限分析计算误差的主要来源。为了对计算网格进行优化,从而有效地降低数值离散误差,基于前沿推进网格划分技术并以单元内能量耗散率的相对大小为控制指标,提出了一种有限元上限分析的网格自适应策略。首先,引入前沿推进网格划分技术,实现在网格生成过程中对单元尺寸和形状的灵活控制;其次,将当前计算网格中各单元能量耗散率的相对大小转化为新计算网格中单元尺寸的分布信息,并以此指示新计算网格的生成,成功地实现了有限元上限分析计算网格的自适应优化;最后,通过算例分析验证了所提出方法的有效性。     

展馆建筑四维空间的时空理念探索研究

介绍了空间与时间的一般定义,引入展览馆建筑“四维空间”的时空设计理念,针对某展览馆的设计方案,从整体构思入手,通过进行展馆方案设计“四维空间”的探索研究,理解时间与空间的微妙关系,以便在进行展馆建筑设计时通过空间的创造来表现时间的意境,实现展馆建筑“四维空间”的时空理念。     

拓扑学在建筑中的应用——以莫比乌斯住宅与克莱因瓶住宅为例

莫比乌斯与克莱茵瓶是拓扑几何学中典型的特例，拥有一般几何形所不具备的奇异特性，本文便以莫比乌斯住宅和克莱茵瓶住宅为例，介绍了拓扑几何学在建筑设计当中的应用。     

旧城文脉的延续与空间的完善--以珠海市莲花路街区立体化改造为例

珠海市莲花路街区存在商业空间不成系统、商业集聚力缺乏、公共空间缺乏活力、步行街过大的人流量影响地面环境等问题,需对其进行城市空间的立体化改造.规划保留旧的城市轴线以延续城市文脉,开辟新的城市轴线以发展和完善城市空间,并力图使新的休闲娱乐轴线与莲花路历史文化轴线实现有机结合.     

建筑设计基础课程中形态构成系列的教学研究与实践

“三大构成”系列是我国大多数建筑院校低年级建筑设计基础课程中一个重要的训练环节,但是源于“包豪斯”的这个设计基础系列课程在我国建筑院校中一直以来却是以美术院校的构成训练为参考,从教材到课题设置均是基于工艺美术的标准,实践证明这正是建筑类院校的学生无法在建筑创作中正确体会和运用构成知识,创造优美协调的建筑形体的重要原因。有鉴于此,华南理工大学建筑学院的“建筑设计基础”课程中,目标明确地提出了基于建筑学的构成系列训练课程,多年的教学实践证明,这种有针对性的训练,对于建筑院校学生掌握构成系列知识来进行建筑的分析和创作,有着非常直接的良好教学效果。     

长江三峡区八字门滑坡稳定性分析与评价

在研究了三峡库区秭归县八字门滑坡的工程地质条件及滑坡体基本特征的基础上,介绍了该滑坡的结构及变形特征,从滑坡形成条件和诱发变形因素两方面分析了滑坡形成的原因及诱发坡体失稳的主要因素.在不同工况下及地震作用下对滑坡体进行稳定性计算,结果表明,在库水位变化和暴雨情况下滑坡处于不稳定状态,极有可能复活.     

瑞安飞云江三桥斜拉桥索力测试及评价

以瑞安飞云江三桥为对象,介绍了独塔斜拉桥斜拉索的索力测试,并将测试结果与设计值进行对比,得出除少数拉索外该桥实际索力与设计索力基本一致的结论。     

Sewage sludge-based adsorbents: A review of their production, properties and use in water treatment applications

The imposition of more stringent legislation governing the disposal and utilisation of sewage sludge, coupled with the growth in its generation and the loss of traditionally accepted disposal routes, has prompted a drive for alternative uses for sewage sludge. One option that exhibits especial promise, due to its potential to valorise the sludge, is the conversion of the sludge into adsorbents. This paper seeks to review the published research in this field: it covers the means of production, the characteristics and the potential applications of sewage sludge-based adsorbents (SBAs). The literature has indicated that chemical activation utilising alkali metal hydroxides is the most effective technique for producing high surface area SBAs. In addition, acid washing is highly effective at raising the BET surface area of SBAs, especially when coupled with physical activation. Due to their relatively low microporosity, the phenol uptake of SBAs produced by physical activation is low, but through a combination of their favourable surface chemistry and relatively high mesoporosity, the best of these adsorbents can attain high uptakes of organic dyes. The SBAs produced by carbonisation, through their high cation exchange capacity, generally exhibit a high metal cation capacity. For further research, the following investigations are recommended: the utilisation of alternative chemical activation reagents; the optimisation of the most effective chemical activation techniques; the combined utilisation of different activation and surface chemistry modification techniques to produce application-specific adsorbents.     

Photodegradation study of three dipyrone metabolites in various water systems: identification and toxicity of their photodegradation products

The photochemical behaviour of three relevant metabolites of the analgesic and antipyretic drug dipyrone, 4-methylaminoantipyrine (4-MAA), 4-formylaminoantipyrine (4-FAA) and 4-acetylaminoantipyrine (4-AAA), was evaluated under simulated solar irradiation (Suntest system). For 4-MAA, different aqueous solutions (synthetic seawater, freshwater and Milli-Q water) as well as different operational conditions were compared. According to the experimental results, 4-MAA resulted as being an easily degraded molecule by direct photolysis, with half-life times (t1/2) ranging from 0.12 to 0.58 h, depending on the irradiation conditions. Faster degradation was observed in synthetic waters, suggesting that the photolysis was influenced by the salt composition of the waters. However, no effect on the degradation rate was observed by the presence of natural photosensitizers (dissolved organic matter, nitrate ions). 4-FAA and 4-AAA showed slower photodegradation kinetics, with t1/2 of 24 and 28 h, respectively. A study of photoproduct identification was carried out by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-time-of-flight mass spectrometry (LC-TOF-MS) (ESI positive mode), which allowed us to propose a tentative photodegradation pathway for 4-MAA and the identification of persistent by-products in all the cases. Finally, the application of an acute toxicity test (Daphnia magna) showed an increase in toxicity during the photolytic process, a consequence of the formation of toxic photoproducts.     

舞动的清河,儒雅的书院——河北省清河县“三馆一场一校”规划设计方案

该文基于河北省清河县"三馆一场一校"规划设计方案,以"舞动的清河、儒雅的书院"为线索,对用地布局、空间组织、景观绿化、道路系统等进行了分析,并对城市化进程中小城市文化体育中心的规划设计进行了一定的探索。