黄土隧道衬砌背后空洞对隧道衬砌结构影响分析

衬砌裂损是隧道病害中常见的问题,也是严重威胁结构安全的一个重要因素。文章针对铁路运营隧道病害的检测结果,对衬砌背后空洞进行平面弹塑性计算分析,得出不同位置、不同大小的空洞以及空洞群对结构各截面受力及位移影响的系统认识,明确提出衬砌结构与围岩结合的不紧密性是恶化衬砌受力条件、造成围岩进一步松动、进而造成衬砌裂损的一个重要原因;还对直墙式及曲墙式衬砌所受到的不同影响进行了比较分析,认为曲墙式衬砌拱部结构能较好地将内力传递给边墙,由边墙部分承受较大的水平抗力,优化了整体结构的受力,从而降低背后空洞对衬砌结构的影响。通过对计算结果的系统分析和研究,合理解释了实际检测中的问题。     

论职业辅导沿着"信息化道路"发展

随着互联网的发展，网络在职业辅导中的应用逐渐深入广泛，但也带来了一些问题。合理利用网络开展职业辅导，从而沿着“信息化道路”发展，这是一个新的挑战，也是未来的发展趋势。     

富溪隧道进口滑坡构造特征分析

从评述富溪隧道进口右侧边坡的地貌、岩性、构造、地表水和地下水特征入手,结合调查资料,对滑坡的构造、形成原因和继续活动的可能性进行分析,并就滑坡对隧道的影响进行论证,提出处理建议。     

双键位置对分子隧道结电子传输特性的影响

采用金属镓作为电极材料,利用分子自组装技术构筑了C7H15OH、C4H9CH=CHCH2OH、C3H7CH=CHC2H4OH、C2H5CH=CHC3H6OH和CH3CH=CHC4H8OH共5种有机分子的毛细管隧道结.在常温下,可以测得分子隧道结的I-V曲线和dI/dV-V曲线.研究表明:分子隧道结明显地体现出非线性的电子传输特性,具有整流的性能;饱和有机分子的隧道结比不饱和有机分子的隧道结更难进行电子传输;结构相似但双键位置不同的有机分子,双键位置的变化对分子隧道结电子传输特性的影响不大.     

Test and Analysis of an Existing Tunnel Vibration Induced by Blasting Construction of Diaphragm Wall

According to the blasting construction of the diaphragm wall of Puxi approaching section of East Fuxing Road river-crossing tunnel, the monitoring project of the vibration of the existing tun-nel induced by the blasting construction is put forward, which includes the sensors’ location, moni-tor method and the vibration monitoring system. Based on the monitoring data of the explosion vibration, the vibration wave forms, velocities, acceleration responses, main frequencies and fields of measure points are analyzed under the conditions of three locations and different charge quanti-ties. According to the safety-judging standard of explosion vibration, the conclusion that the exist- ing tunnel is safe under the explosion vibration is then drawn. Furthermore, the spectrum character-istics of three explosion vibrations and the spectrum changing properties of explosion vi-bration wave transmitting in different directions are concluded, which can provide reference to similar projects.     

Simplified analysis for reflective overpressure on walls of rectangle-section tunnel due to its inner-explosion

Based on the constructing thought of the displacement model of isoparametric finite element, an extended interpolating algorithm is deduced for calculating the overpressure history of an optional point on the walls of the rectangle-section tunnel under an optional point-explosion in its internal space. According to the working principle, the overpressure histories of all nodes on the walls of a tunnel with the equal width and height of 2 m, induced by a reference-charge explosion at each node in this tunnel's cross section, are computed using the LS-DYNA software, and then are gathered to establish a reference database, which makes it possible to set optionally the positions of the explosive and the overpressure-observed point. In addition, some variation factors of peak values and durations of overpressure on the walls, reflecting some changes on the charge weight and the sizes of width and height of the section, are included in this algorithm in order to simulate approximately the overpressure responses on the walls under the optional charge weight and cross-section size. Some example analyses indicate the rapidity and validity of this method, and therefore this will bring it a good prospect in engineering application.     

试论我国燃油税改革

从1994年我国动议燃油税改革到今天已经过去了14年,燃油税至今仍未出台,国际油价却在一路冲高,原油期货价格已冲至100多美元一桶。广大车主一方面承担着高油价,一方面缴纳着不菲的养路费,社会各界都在呼吁尽快开征燃油税,以实现节约能源和社会公平。本文即通过对相关问题分析来探讨我国燃油税改革复杂背景和影响。     

大梁山隧道围岩稳定性研究

在野外隧道工程地质条件调查的基础上，通过岩体结构分析判断潜在破坏方式，经验估算方法获取节理抗剪强度参数，运用块体理论评价了大梁山隧道的围岩稳定性。     

公路工程测量技术实训教学的研究与实践

通过长期公路工程测量技术实训教学的研究与实践,结合该校教学与公路工程施工状况,面向工程实践,提出公路工程测量技术的实训教学内容,拓展了实训教学的形式,完善了实训教学的体系。采取多种实训教学手段,对公路工程测量技术要求的工程生产能力进行培养。     

流场可视化的便携式烟风洞装置

文章介绍了一种整体长度为0.64m,重约为4kg,轻巧、便携的烟风洞装置的特点.该装置有着良好的烟气发生装置和烟气流动质量,方便的燃油补充机构和试件磁力固定结构,是流体力学学科中一种较完美的教学工具.轻巧的结构使得这种烟风洞装置可以很方便地携入教室用于教学演示.各种研究对象在风洞中的绕流情况可以很好地用高质量的数字照片显示出来,这些照片如圆柱绕流,平面叶栅的流线分布,都能较好地反映了流体力学流动基本规律;同时,通过对一个模型汽车所进行的流体力学数值计算（FLUENT）与实验对比,其结果显示出它们的流动状态吻合较好,说明这种便携式烟风洞的良好性能.