渝利铁路都亭山隧道缓倾岩层施工控制技术

分析了渝利铁路都亭山隧道缓倾岩层对隧道开挖的影响,具体阐述了缓倾岩层等不良地质条件下进行隧道开挖掘进的开挖方法和技术措施,经实践取得了良好效果,为类似隧道工程开挖积累了宝贵经验。     

浅埋暗挖法在小导管注浆加固施工中的应用

所谓小导管注浆加固地层技术，指的就是顺着隧道开挖轮廓线外，并纵向往前倾斜设置注浆管，同时把浆液注入进去以起到止水与超前加固围岩的效果，当然还具有超前管棚预支护效用。     

十天高速公路软弱围岩隧道快速施工技术

结合十天高速公路隧道工程施工经验,介绍了软弱围岩隧道快速施工技术,具体阐述了隧道开挖模式和钻爆施工方案及其出渣机械配置,并对初期支护方法和各工序交叉衔接施工及作业时间进行了说明,为今后类似隧道施工积累了经验。     

Comparison of the Ewald and Wolf methods for modeling electrostatic interactions in nanowires

Ionic compounds pose extra challenges with the appropriate modeling of long‐range coulombic interactions. Here, we study the mechanical properties of zinc oxide (ZnO) nanowires using molecular dynamic simulations with Buckingham potential and determine the suitability of the Ewald (Ann. Phys. 1921; 19) and Wolf (J. Chem. Phys. 1999; 110 (17):8254–8282) summation methods to account for the long‐range Coulombic forces. A comparative study shows that both the summation methods are suitable for modeling bulk structures with periodic boundary conditions imposed on all sides; however, significant differences are observed when nanowires with free surfaces are modeled. As opposed to Wolf's prediction of a linear stress–strain response in the elastic regime, Ewald's method predicts an erroneous behavior. This is attributed to the Ewald method's inability to account for surface effects properly. Additionally, Wolf's method offers highly improved computational performance as the model size is increased. This gain in computational time allows for modeling realistic nanowires, which can be directly compared with the existing experimental results. We conclude that the Wolf summation is a superior technique when modeling non‐periodic structures in terms of both accuracy of the results and computational performance. Copyright © 2010 John Wiley & Sons, Ltd.     

隧道二次衬砌泵送混凝土配合比设计探索

根据慈母山隧道结构设计混凝土的强度,以及在特殊条件下混凝土的耐久性、和易性等技术要求,并结合本工程混凝土运输时间及气候条件、混凝土泵的性能、原材料的质量等实际情况,合理选用了原材料及其用量间的比例关系,从而设计出经济合理、质量好、泵送效率高的混凝土。     

黄土隧道施工工艺

以张家沟隧道工程为例，结合工程地质条件和黄土特征，介绍了黄土隧道的施工方法，重点阐述了黄土隧道的施工控制技术和施工工艺及注意事项，为今后类似工程的施工提供参考。     

The use of micro-simulation for congested traffic load modeling of medium- and long-span bridges

This paper presents a new approach to the modeling of congested traffic loading events on long span bridges. Conventional traffic load models are based on weigh-in-motion data of non-congested traffic, or something similar to a Poisson Arrival process. In neither case do they account for the mixing between lanes that takes place as traffic becomes congested. It is shown here that cars move out from between trucks as traffic slows down which results in a higher frequency of long platoons of trucks in the slow lane of the bridge. These longer platoons increase some characteristic load effects under the slow lane by a modest but significant amount. Micro-simulation, the process of modeling individual vehicles that is widely used in traffic modeling, is presented here as a means of predicting imposed traffic loading on long-span bridges more accurately. The traffic flow on a congested bridge is modelled using a random mixing process for trucks and cars in each lane, where each vehicle is modelled individually with driver behaviour parameters assigned randomly in a Monte Carlo process. Over a number of simulated kilometres, the vehicles move between lanes in simulated lane-changing manoeuvres. The algorithm was calibrated against video recordings of traffic on a bridge in the Netherlands. Extreme value statistics of measured strains on the bridge are then compared to the corresponding simulation statistics to validate the model. The micro-simulation algorithm shows that the histograms of truck platoon length are moderately affected by lane changing. This in turn is shown to influence some characteristic load effects of the bridge deck.     

长治县陶清河水库应急专项除险加固工程

以陶清河水库工程为例,介绍了水库的地理位置、区域环境等,针对工程现场检查发现的输水洞渗水严重的问题,对其原因进行了剖析,确立了解决方案,并阐述了具体的施工技术,指出及时排除输水洞存在的各种病险,对提高大坝的安全性、耐久性具有重要意义。     

使用Cisco路由器模拟测试IPv6隧道技术

IPv4向IPv6的迁移更好的解决了网络容量及网络性能。本文重点论述在Cisco路由器上如何模拟手动隧道及自动隧道两种传输方式,并就其工作原理和实现过程进行了较为详细的分析和概括。同时,对IPv6技术做了一定的预测。