哈尔滨市松花江隧道顶部覆土安全厚度预测模型

针对拟建哈尔滨市松花江隧道的施工过程，首先假定考虑各种不同工况及场地条件下的40种施工设计模型，建立尽可能逼近实际问题的有限元数值分析模型，反复进行模拟计算，据此绘制各单项影响因子与隧道顶部覆土安全厚度之间相互变化关系曲线，并分别给出其高精度的拟合关系式。同时讨论各单项影响因子与隧道顶部覆土安全厚度之间的相关变化规律，从而遴选出影响隧道顶部覆土安全厚度的主要影响因子，然后采用多元逐步回归分析方法，获得能够综合体现各主要影响因子共同作用的隧道顶部覆土安全厚度预测模型。最后，以一相似的隧道工程为例，对所得到的隧道顶部覆土安全厚度预测模型进行有效性与可靠性校验。     

猎德污水处理厂(四期)加盖A2/O生化池设计浅谈

结合某污水处理厂改良A2/O生化池设计实例,介绍大型钢筋混凝土加盖池体如何合理进行池体盖板结构布置以及合理设置贯穿池体盖板、底板及壁板的变形缝.为避免贯通缝打断池体盖板梁板结构,解决池体盖板支承困难,本工程采取沿池体壁板设置通长条状牛腿等方法予以解决,另外也给出了试水工况下分块池体在深水压为作用下的抗滑移设计方法.     

Impacts of climate and land‐cover changes on water resources in a humid subtropical watershed: a case study from East Texas,USA

This study investigates the response of water resources regarding the climate and land‐cover changes in a humid subtropical watershed during the period 1970–2009. A 0.7°C increase in temperature and a 16.3% increase in precipitation were observed. Temperature had a lower increase trend, and precipitation showed definite increasing trend compared to previous studies. The main trend of land‐cover change was conversion of vegetation and barren lands to developed and crop lands affected by human intervention, and forest and grass to bush/shrub which considered to be caused by natural climate system. Hydrologic responses to climate and land‐cover changes resulted in increases of surface run‐off (15.0%), soil water content (2.7%), evapotranspiration (20.1%) and a decrease in groundwater discharge (9.2%). We found that surface run‐off is relatively stable with precipitation, whereas groundwater discharge and soil water content are sensitive to changes in land cover, especially land cover brought about by human intervention.     

型钢混凝土临界保护层厚度研究

通过建立拉断破坏模型、剪切破坏模型和基于塑性极限分析的上限定理,经过理论推导得出型钢混凝土的临界保护层厚度,并将所得结果与试验值、规范规定值进行比较,本文为型钢混凝土的粘结滑移性能的研究提供了重要参考。     

高层建筑中高性能混凝土施工要点分析

结合夏日港湾工程，介绍了高层建筑中高性能混凝土的施工技术及质量控制要点，总结了施工过程中的有关注意事项，实践证明，这些技术与方法对保证高性能混凝土的质量是行之有效的。     

楼板支座负筋保护层厚度过大的静载试验研究

对某支座负筋保护层厚度过大的楼板进行了现场荷载试验,对变形、裂缝宽度进行了测量,并与规范允许值进行对比分析,验证了该楼板能否满足正常使用性能,从而确保了该楼板的安全性。     

钢筋保护层混凝土细观界面过渡区优化及耐久性

针对传统混凝土结构及构件钢筋保护层混凝土寿命较低,耐久性不良的现状,通过对普通混凝土细观层次上（50～100 μm）的浆－骨界面过渡区进行优化或改善,以耐久性设计为主要目标,设计制备出内部细观界面大幅度优化的高致密保护层混凝土（High dense concrete cover,简称HDC）,并针对其抗渗性、抗钢筋锈蚀、抗酸性气体腐蚀以及抗冻性等耐久性能展开系统的试验研究。结果表明,所制备的HDC抗渗性优良,评价结果为渗透性“非常低”;HDC抗钢筋锈蚀性能相比普通混凝土保护层得到大幅度增强;在CO2、S     

A fieldwork study on the diurnal changes of urban microclimate in four types of ground cover and urban heat island of Nanjing,China

Records of the past years showed that the climate of built-up regions differs significantly from rural regions and one of the most obvious and important modifying effects of urbanization on local climate is the urban heat island (UHI). In this paper, four types of land cover, namely urban bare concrete cover, urban woods or the shade of trees, urban water areas and urban lawn, were selected to study their microclimate, and the UHI was also analyzed using air temperature data measured at four fixed observation spots in Nanjing, China, during hot weather from July to September, 2005. Dry and wet bulb temperature data were obtained by whirling psychrometers, and wind speed data by cup anemometers. Our observed data focused on the detailed statistical analysis of the microclimate variation in the four types of land cover during the whole day. The results showed that: (1) the microclimate of these four types of land cover had significant differences among different observation sites. In general, the air temperature of these four types of land cover complied with the order during daytime: bare concrete cover>lawn>water areas>woods or the shade of trees, with reversed order during nighttime when the air temperature of the lawn became the lowest. Compared with the bare concrete cover, the other three types of land cover showed the effect of dropping air temperature ranging between 0.2 and 2.9 °C. There were some instant dynamic characteristics in detailed temporal series among these four types of cover in the different observation sites. (2) The UHI effect could be detected obviously by the air temperature difference between the urban center area and the rural area. The average UHI intensity during the monitoring period was between 0.5 and 3.5 °C; however, there were also significant day-to-day variations. A strong UHI effect usually occurred around midnight; while about 2–3 h after sunrise the UHI began to decrease till midday time; and during 13:00–15:00, the UHI effect had a sudden increase and then decreased again; after sunset, a peak UHI effect was frequently observed during 18:00–21:00. (3) Finally, by means of the standard deviation (SD), this paper provides a concise and comprehensive understanding for the temporal and spatial microclimatic dynamics of these four kinds of urban cover in the four observation sites. Air temperature at the height of 1.5 m in Nanjing showed that the nocturnally horizontal temperature gradient was somewhat different from that reported in other large cities, and a marked heterogeneity in a smaller ground cover scale could be detected from the microclimatic spatial pattern. There is no doubt that the analysis of these four types of land cover presents the insight into possible countermeasures to decrease the high air temperature in hot summers, and is relevant to the urban planning redevelopment.     

探地雷达在箱梁腹板检测中的应用

介绍了探地雷达的工作原理和利用探地雷达技术对箱梁腹板的检测与应用研究,对箱梁腹板典型的质量问题进行总结。结果表明,探地雷达能够对混凝土的质量缺陷给出直观的雷达波形特征,能够判断钢筋保护层厚度,并实现对腹板内波纹管的准确定位。     

隐身罩拉深模设计

分析了隐身罩零件的结构和工艺特点,改变了组焊式的制造方法,有针对性地制定了模具设计制造工艺方案,简化了设计结构,并以DYNAFORM软件进行了设计计算及模拟。结果表明,提高了模具设计制造效率及准确性,满足了批量生产,且提高了外观质量。