建筑给排水工程节能技术的研究

随着建筑技术的快速发展,建筑节能技术已经成为建筑工程设计的重要内容。建筑给排水工程中的节能技术已然成为广大建筑人士探讨的热点话题,科学合理的节水节能方案,是一项利国利民的大事。基于此,本文将探讨建筑给排水工程的节能技术。     

基于时空关系的盾构开挖地表沉降规律

基于武汉地铁四号线某区间隧道盾构开挖引起的地表沉降数据分析,考虑地表沉降的时空关系,将地表沉降划分为无影响阶段、前期沉降阶段、通过阶段、盾尾空隙沉降阶段、工后沉降阶段,并给出了各个阶段的大致范围及其地表沉降占总沉降的比值。通过对Mindlin解引入时间参数,针对不同阶段地表沉降影响因素进行分析,在前影响距离范围内,盾构机与土体的摩擦力和地层损失对地表沉降的影响占优,在后影响距离范围内,地层损失对地表沉降起到了绝对的控制作用,前期沉降阶段的土层隆起与正面附加推力、摩擦力有关,而正面附加推力、摩擦力和注浆压力导致了工后沉降阶段的土体回弹,由此获得了实时地表沉降预测的理论公式。研究结果表明:理论预测值与实测值能较好的吻合,该公式能够较为准确地实时预测地表沉降。     

An analytical solution to wellbore stability using Mogi-Coulomb failure criterion

Deep wellbores/boreholes are generally drilled into rocks for oil and gas exploration, monitoring of tectonic stresses purposes. Wellbore and tunnel in depth are generally in true triaxial stress state, even if the ground is under axisymmetric loading condition. Stability of such wellbores is very critical and collapse of wellbore must be avoided. Mogi-Coulomb failure criterion is a better representation of rock strength under true triaxial condition. In this paper, an analytical solution is proposed using Mogi-Coulomb failure criterion. The solution is obtained for rock mass exhibiting elastic-perfectly plastic or elastic-brittle-plastic behaviour considering in-plane isotropic stresses. The proposed solution is then compared with exact analytical solution for incompressible material and experimental results of thick-wall cylinder. It is shown that the results obtained by the proposed analytical solution are in good agreement with the experimental results and exact analytical solution. A reduction of about 13%–20% in plastic zone from the proposed closed-form solution is observed, as compared to the results from the finite element method (FEM) based Mohr-Coulomb criterion. Next, the influences of various parameters such as Poisson's ratio, internal pressure (mud weight), dilation angle, and out-of-plane stress are studied in terms of stress and deformation responses of wellbore. The results of the parametric study reveal that variation in the out-of-plane stress has an inverse relation with the radius of plastic zone. Poisson's ratio does not have an appreciable influence on the tangential stress, radial stress and radial deformation. Dilation angle has a direct relation with the deformation. Internal pressure is found to have an inverse relation with the radial deformation and the radius of plastic zone.     

A new chip-thickness model for performance assessment of silicon carbide grinding

The chip-thickness models, used to assess the performance of grinding processes, play a major role in predicting the surface quality. In the present paper, an attempt has been made to develop a new chip-thickness model for the performance assessment of silicon carbide grinding by incorporating the modulus of elasticities of the grinding wheel and the workpiece in the existing basic chip-thickness model to account for elastic deformation. The new model has been validated by conducting experiments, taking the surface roughness as a parameter of evaluation .     

建筑的形态、环境与光伏系统输出功率差异

建筑及其环境的原因可造成串、并联在一起的同样的光伏电池组件形成不同的输出功率。一定程度的输出功率差异不仅使总输出功率减少,而且会在电池板上产生热斑效应,损害电池寿命。探讨了与建筑形态、环境有关的使建筑光伏系统中产生输出功率差异的污垢、阴影以及非平面方面的原因,以及当功率差异无可避免时的处理方法。     

管棚-大断面箱涵暗顶技术在下穿公路工程中的应用及分析

某宽断面公路与公路交叉工程,为在施工期间不中断既有干线公路的正常通行,采用管棚支护下的大断面箱涵暗顶法进行无损下穿,规模大、技术难度高.介绍了管棚、箱涵及其配套设施的设计与制作情况;重点分析说明了"吃土顶进、泥浆润滑"的暗顶施工工艺;论述了对箱涵姿态等进行全过程独立监测的必要性及监测内容;实时指出了该工程在具体操作过程中存在的不足之处.在此基础上再考察比较其他类似工程,着重在公路下穿工程建设的宏观管理方面,特别是方案的制定、技术经济比较、决策选择等方面,总结了经验教训,认为总体上采用下穿方案是适宜的,但更应该因地制宜采取合适的下穿方式,并要未雨绸缪制定周密的施工工艺,才能又好又快地实现建设意图.对于最复杂的暗顶下穿方式,得力的参建队伍、可靠的支护、有效的润滑这三个最基本的要素缺一不可,否则只能事与愿违.这些有益的结论和体会,可为其他类似工程提供借鉴.     

Construction and field measurement of high-speed railway test embankment built on Indian expansive soil “Black Cotton Soil”

The railway embankment applied to high-speed railways is required to have high performance in terms of strength and deformation characteristics. Especially in the case of railway embankments that support slab tracks, the allowable settlement is very small. There are two technical challenges in constructing high-speed rail embankments to support slab tracks in India. The first challenge is dealing with problematic black cotton soil (BCS), which is widely distributed in India but very unusual soil in Japan. The second challenge is posed by the strict deformation requirement in the construction of the embankments. In this study, a 6 m-high test embankment was constructed on BCS in India. The deformation of the embankment and changes in water content were measured over a period of 18 months. In the construction of the test embankment, two different BCS countermeasures were applied. The results of the tests on this embankment were compared with those from an embankment without countermeasures. Complicated deformation behaviors, including settlement and the uplift of embankment, were observed in the section without countermeasure. However, in the embankment with cement-mixed gravelly soil (CGS) slab improvement with geosynthetics, the much lower amplitude of embankment deformation is evidence of the effectiveness of this countermeasure. The cohesive non-swelling soil (CNS) layer applied immediately below the embankment to reduce the water content fluctuation of BCS was not effective enough for use for high-speed railway embankment. Besides determining the technical challenges for the BCS countermeasures, the results of this study confirmed that a high-performance embankment can be constructed with Indian embankment material by performing sufficient compaction management.     

浅谈建筑与城市空间文化特色的塑造

本文通过分析建筑与城市空间的构成要素,论述了自然环境与社会环境对建筑与城市空间文化特色的影响,并从城市的肌理、空间的融合与共享、风格的协调与对比等方面论述建筑与城市空间文化特色的塑造。     

重庆市城镇住宅建筑能耗的统计分析

该文首先对重庆市2000-2009年期间城镇住宅建筑能耗各项构成进行了统计;其次,在其基础上计算了历年及各时期城镇住宅建筑单位面积能耗,并分析了各种能源消耗历年来的变化趋势;最后,依据我市城镇住宅建筑耗能的结构,指明了我市城镇住宅建筑节能的方向。