透水人行道面表面水渗入率的确定与验证

对新型透水人行道面表面水渗入率,用渗水仪模拟试验方法和模拟降雨试验方法进行测试和分析,得出了联锁块人行道面表面水渗入率,并通过现场依托工程试验路的验证,提出了符合实际使用条件的表面水渗入率设计参数,为多雨地区设计透水人行道面提供依据。     

高等级公路路面渗水试验分析

水渗入路面会对沥青混凝土面层产生不利影响。为了分析路面水的渗入量,为高等级公路的排水设计提供直接的依据,对同三国道进行了现场汇水渗透试验。详细介绍了现场渗水试验的方案和过程,对路面的入渗特征、渗入率、接缝对路面入渗的影响,以及边缘排水系统的排水效果进行了系统分析。发现新建的沥青普通混凝土面层的渗水明显,设置路面内部排水系统非常必要。     

城市高压天然气储气管道的优化设计

文章根据高压管道的水力计算公式、强度计算公式和高压管道储气量稳态计算模型,得出了用于储气目的的高压管道的金属耗量/储气量比率模型。通过分析发现管径和长度对储气管道的金属耗率影响小,而设计压力对金属耗率影响大,并且存在一个使金属耗率最小的最佳设计压力和最佳管径。     

排水系统地下水渗入量的水力学模型辅助评估

基于水量平衡原理,通过管道水力模型计算与现场流量及水位监测,研究考察了不能直接应用夜间最小流量法的水泵强制排水系统地下水渗入量的水力模型辅助评估方法,据此评定了上海市某混接雨水系统旱流截污运行条件下的地下水渗入量,并对该方法的应用条件进行了分析讨论,为排水系统管理与地下水渗入量研究提供了借鉴。     

烟气渗入竖井的压力中性面与开口质量流率计算

介绍无烟气持续渗入竖井和有烟气持续渗入竖井的中性面与质量流率计算模型,研究火灾时竖井的烟囱效应。根据质量平衡与热量平衡推导竖井开口质量流率与竖井内部压力中性面位置的计算方法,并进行简化。选取横截面内部尺寸为4 m×4 m、高度为304 m、顶部与底部开口的面积4 m2的竖井,设定火灾烟气从50 m高处连续渗入到竖井内部空间,渗入烟气的初始温度为177℃,烟气渗入的质量流率为10、20、30 kg/s,对比分析理论计算结果与FDS模拟结果。研究发现,KLOTE模型获得的压力中性面位置明显高于数值模拟结果,且该偏差会随着烟气渗入质量流率的增大而增大。提出的简化计算方法与数值模拟结果的差异较小,具有可靠性与高效性。     

上海市排水管道渗入量调查与修复决策

根据上海市排水管道的实际状况和现有水平,分析了影响上海市地下水渗入较为严重的主要因素,介绍了排 水系统地下水渗入量调查的操作程序,提出了管道修复决策的依据,确定了修复工程的经济顺序,对我国南方高地下水 位地区排水管道的维护管理具有借鉴意义。     

HRBF500 RC柱地震全过程损伤试验分析

根据6根配置HRBF500级细晶钢筋的混凝土柱的低周反复加载试验,计算不同轴压比、剪跨比和配箍率构件的屈服位移和滞回耗能。根据经典Park模型存在的若干问题,引入比例参数协调低周反复加载极限位移与单调加载极限位移的关系,并局部修正Park模型。最后,对6个构件进行了加载全过程的损伤分析,总结损伤趋势和规律,分析轴压比、剪跨比和配箍率对损伤发展趋势的影响,并给出相应损伤评价准则和设计建议。     

玻璃幕墙渗水原因分析及防治措施

对玻璃幕墙渗水原因从设计、材料、施工及使用等方面进行了研究分析,提出了防治措施,以消除孔隙、水和渗入裂缝压力差的存在。     

沥青混合料转运车试验研究

本文在分析沥青混合料转运车的工作原理及作用的基础上,根据相似理论,设计了沥青混合料转运车相似模型,试验揭示了其结构参数对改善沥青混合料离析程度的影响,得出了材料离析率与螺旋轴转速、螺距及螺旋半径之间的关系,为沥青混合料转运车的设计开发提供科学可靠的依据。     

浅埋并行隧道间距对管片内力影响的分析

浅埋并行近距离隧道的设计施工是盾构隧道研究中的难点。针对间距对管片内力影响的问题,建立了包括地层、等代层、衬砌的有限元计算模型,并通过工程算例验证了该模型的合理性。然后计算隧道间距、埋深、土体参数等因素对隧道周围土体应力、管片内力的影响。根据土体应力结果可知,净距的减小使两隧道的卸载区相互接近或重叠,使两隧道之间土体承受较大荷载,发生屈服,从而使管片内力增大。根据管片内力结果得到了不同情况下管片最大内力提高率,得知埋深和土体黏聚力对提高率的影响较弱,土体内摩擦角的影响较为显著,并给出了各种情况下管片内力设计值提高率的取值大小。最后综合分析结果,针对浅埋并行超近距离隧道问题,给出了设计施工建议。     

生态混凝土路面透水特性研究

针对目前硬质路面存在的问题,通过对生态混凝土雨水入渗特性实验研究,分析其对地表径流的削减作用,结果表明生态混凝土具有较高的透水率,透水路面对地表径流具有明显的削减作用,以期促进生态混凝土在道路工程中的应用。     

Analysis of rainfall infiltration effects on the stability of pyroclastic soil veneer affected by vertical drying shrinkage fractures

The paper presents a preliminary, simplified evaluation of the effects of rainfall infiltration on the stability of slopes in layered pyroclastic soils affected by shrinkage vertical fractures. The analysis has been developed with a special reference to a stratigraphic sequence obtained by an in situ survey at Pizzo d’Alvano (Southern Italy). The analysis of rainfall infiltration is performed using an original dual-permeability model. Results show how fractures strongly condition infiltration depending on rainfall intensity. Prolonged low-intensity rainfall may lead to a higher saturation of the surface soil layer than short, intense rainfall when water may flow quickly through fractures into the underlying more permeable soil layers. Calculated distributions of pore pressure are used for the slope stability analysis using the infinite slope approach. Variations of the safety factor as a consequence of infiltration show that prolonged rainfall can induce a more relevant decrease in the safety factor than intense precipitations.     

Comparative analysis of the novel infiltration model with other infiltration models

Variability in infiltration characteristics of soils creates need for selection of appropriate infiltration model. Recently, a novel infiltration model was proposed and reported to perform excellently in estimating infiltration rate of soils of Kurukshetra, India, however, this model need to be tested for its reliability at global level. In this regard, the present study analyses the reliability of the novel model based on infiltration database comprising of 16 data sets from different parts of the world to arrive at some generalized results on the reliability of novel model as compared to commonly used infiltration models. Comparative analysis reveals that out of the 16 data sets for 9 sites (57%). Horton model was found to be best model while novel model was found as best‐fit model in five cases (31%). Based on the present study and earlier investigations, it may be inferred that novel model could be a useful model to estimate infiltration rate in loams.     

新行标《城镇道路路面设计规范》编制的思路

为适应城镇道路建设发展的需要,编制了行业标准CJJ169—2012《城镇道路路面设计规范》。介绍了规范中主要条文内容与编制思路,包括了强制性条文与节能减排条文的规定、可靠度设计、沥青路面结构设计指标体系的完善、材料性能要求的提高及透水人行道的设计等方面内容,填补了目前城镇道路路面设计领域的技术标准空白;同时开发了路面结构设计专用软件。     

低噪音透水路面在城市街巷改造中的探索实践

通过某城市街巷道路改造工程实践,介绍了低噪音透水路面在改造工程中的应用,就相关技术要点及项目实施情况作了阐述,实践证明:各项预期指标完成情况良好,路面等级明显提高。     

Runoff infiltration to permeable paving in clogged conditions

The effect of varying runoff on a clogged permeable surface was analysed using a specifically designed laboratory rig consisting of a variable gradient testing frame, a rain simulator and water collecting chambers. The results indicate that the apparatus can be used successfully to test the runoff resistance of concrete blocks in permeable surfaces. The results indicate that a surface at 2% gradient that is clogged with crushed construction debris still permits significant levels of infiltration.     

透水性人行道结构的试验研究及分析

我国透水性人行道的研究和使用,尚处于起步阶段。透水性人行道因其可以补给地下水源、减少城市积水、增进交通安全、改善城市生态环境等特点而引起人们关注。本文介绍了透水性人行道的结构特点,通过室内试验、试验段铺设和工程试验的效果观测分析,提出了3种典型的透水性人行道结构型式的建议。     

高速公路路面渗水的环境灾害分析及其治理

本文以广东花清高速公路路面渗水问题为例,进行环境灾害分析并提出有效防治措施。通过现场水文地质试验、岩土测试以及综合环境地质调查,研究结果表明渗水由弱透水层中的潜水引起,连续降雨期间,在各种地质环境因素的共同作用下,弱透水层中的孔隙潜水面上升造成,而潜水的补给来源是分水村环形山谷中的地下水和地表水。针对其成因提出了降水盲沟的治理措施。综合考虑各种环境条件的情况下,通过降低高速公路附近的地下水水位,路面渗水现象得到了较好的控制。该事故表明在岩土工程和环境工程研究中地下水的作用应该作为一种基本环境因素进行考虑,在全球气候发生变化的大环境背景条件下,多学科结合进行环境灾害的危险性评价显得十分重要。     

级配碎石层在2种典型路面结构中的计算分析

以长沙市武广片区道路试验段为依托工程,通过理论分析和3D有限元数值分析、工程应用与后期跟踪检测相结合等技术手段,对级配碎石层应用于2种典型道路路面结构(柔性结构和倒装结构)的性能差异进行了研究。利用大型有限元分析软件ABAQUS建立路面结构的3D模型,充分考虑了级配碎石层的弹塑性,对柔性结构、倒装结构在单次平面均布矩形荷载作用下的力学响应进行了分析;通过变化级配碎石层的回弹模量和厚度,对2种路面结构的力学指标峰值进行了敏感性分析。试验段检测结果表明,采用3D有限元模型分析路面结构能较真实地反映路面结构的实际力学响应。     

The diffuse infiltration of road runoff: an environmental improvement

The Laboratory of Engineering and Environmental Geology (GEOLEP) has been mandated by Swiss authorities (Swiss Federal Road Office FedRO) to test a new road runoff management concept. This concept promotes the diffuse infiltration of road runoff into infiltration slopes designed for this purpose. Soils retain particles and contaminants; this lowers the road impact on the environment and simultaneously improves aquifer recharge. This concept has to be adapted to aquifer vulnerability and traffic conditions. Thus, a real-scale experimental station was designed and built in Switzerland to assess the feasibility of this new concept. This station allowed the testing of two lysimeters composed of 80 cm of A and B-horizons. Water and chemical fluxes were measured at the lysimeter bases. Road runoff was sampled in a distinct collector. Infiltration of road runoff into the local aquifer was monitored thanks to six piezometers. Water quality and quantity were therefore measured at each step of the infiltration process. Results provided by 112 natural events showed that soil horizons accommodated road runoff flows. The least favourable conditions for contaminant retention are encountered during thunderstorms, when high concentrations of substances deposited on the road are remobilised within a short time and rapidly percolates through soil horizons. Thus, three artificial events were designed to mimic heavy thunderstorms. Concentrations measured in road runoff notably decreased after soil filtration. Substances with high distribution coefficients Kd (low mobility) had concentrations reduced to lower values (1/1000 to 1/10,000), while those with high mobility retained similar concentrations even after soil filtration. However, these mobile substances exhibited low concentrations in the underlying aquifer due to dilution. This innovative road runoff management concept can thus be readily implemented outside groundwater protection zones where aquifers are slightly vulnerable; it undoubtedly lowers the environmental impact of roads, does not endanger road integrity, and locally increases aquifer recharge.