已建引水涵洞结构的内力分析

文中以引水涵洞为例，利用有限元软件建立三维有限元数值模型，通过两种工况对引水涵洞进行应力和位移分析。根据计算结果可知，在防洪工况和地震工况时，涵洞结构材料的抗拉强度均超出规范允许值，最终将导致涵洞结构失稳破坏。进而为类似工程设计提供一定参考。     

阶梯形涵洞长度计算方法

针对通过CAD制图来确定梯形涵洞长度既影响工作效率又繁琐的问题,根据实践经验,通过对涵洞长度计算中有关因素进行分析,总结了一种阶梯形涵洞长度计算方法,指出这种计算方法比CAD制图确定阶梯形涵洞长度的方法更简捷,值得推广使用。     

水流冲刷下的涵洞软地基承载性能与加固技术

针对目前研究的涵洞软地基承载性能分析结果不准确，加固技术难以达到要求等问题，在水流冲刷下提出一种新的涵洞软地基承载性能与加固技术。以武汉市武昌区红巷南侧、临江大道东侧、武昌山北地区主要的排渍泵站为例，分析其承载性能，确定加固技术。分析水流冲刷下的涵洞软地基特性，根据物理特性、固结特性与强度特性确定涵洞软地基的刚性特性，建立有限元数值模型，对粘土和砂土地基与涵洞软地基承载力之间的关系进行分析，得到承载力变化规律，研究涵洞软地基承载力随固结变化的情况，计算涵洞软地基承载力。通过降低超静孔隙压力的方式增加涵洞软地基的承载能力，控制涵洞软地基的液化性，实现水流冲刷下的涵洞软地基加固。研究的水流冲刷下的涵洞软地基承载性能与加固技术得到的地基承载力数值与实际值更加接近，加固性能更好，具有很好的实际应用效果。     

斜交涵长的计算新思路

介绍了计算涵洞涵长的基本思路，从直线上斜交涵洞、圆曲线上斜交涵洞两种单级边坡情况分析了考虑半径因素的斜交路段涵长的计算方法，使得涵长计算精度满足工程放样的要求。     

某港口排水涵洞水力计算浅析

文章提出根据规划或已有排水涵洞作为参考往往导致涵洞尺寸偏大,造价偏高,并通过工程实例进行分析,得出排水涵洞进行水力计算,优化设计是必须的。并提出一些工程中的计算经验,为今后类似项目提供参考借鉴。     

东汪庄泵站穿堤涵闸结构设计

东汪庄穿堤涵闸为涵洞式钢筋混凝土双层结构，将闸室与涵洞连为整体，上游与压力池相接，底板为立交涵洞顶板。结构计算复杂。     

高填方路堤下考虑涵洞与土体共同作用的基础结构设计方法研究

国内的现行规范关于涵洞结构设计方法忽略了结构与土的相对压缩变形,人为将涵管结构与土分开计算,涵洞的实际内力与设计计算值有差距从而导致了涵洞在运营期间的大量病害,为减少因结构设计方法不当而导致的涵洞病害,提出了考虑涵洞与土体共同作用的计算模型,并基于此模型进行了考虑变形协调的涵洞基础结构计算,计算结果表明,所提模型考虑更加全面,计算结果更趋于合理。     

涵洞工程施工难题分析与相应的解决措施

本文根据涵洞工程的特点，阐述了涵洞工程施工的难题与解决的思路，并在此基础上论述了半隧道模早拆支模系统涵洞施工技术的运用原理、实施要点及经济前景。     

浅谈高速公路盖板涵洞的设计

以忻保高速公路K188＋774．0盖板涵洞设计为例，介绍了盖板涵洞设计标准及相关规范，着重论述了盖板及涵台计算方法及要点，并提出一些见解，从而为类似盖板涵洞设计积累经验。     

山区高速公路涵洞设计要点探讨

针对山区高速公路涵洞的特点，对山区高速公路涵洞的总体设计、土压力计算理论、地基承载力及地基处理等方面的问题进行探讨。     

Effects of formwork surface materials on concrete lateral pressure

In this study, the effect of formwork surface materials on the concrete lateral pressure was investigated. Seven wall formworks were constructed. Populus nigra timber, pinus silvestris timber, plywood and steel sheet were used as surface materials for these formworks. One of two formwork, which had the same surface material, was watered except for the steel formwork before placing the concrete. Concrete was placed into the formworks and the lateral pressures of concrete on formworks surface were measured by a strain measurement system. As comparison the limiting value of concrete lateral pressure was calculated by ACI-347 equation.It was concluded that, watering the surface of wood formworks increased lateral pressure of concrete on the formworks. Lateral pressure of steel formwork was equal to limiting value of ACI-347 and larger than lateral pressure of populus nigra, pinus silvestris, and plywood formworks. The lateral pressure of pinus silvestris formwork was some less than 3.3%, 7.2%, 21%, respectively, lateral pressure of populus nigra, plywood, and steel formwork”.     

现浇钢筋混凝土方形漏斗施工技术

钢筋混凝土方形漏斗是工业建筑中的一种较常见构件 ,本例通过工程实践 ,总结出一套该构件施工中从模板支撑及异形模板配模、模板的安装及混凝土施工操作注意事项等行之有效的办法 ,在工程实践中具有一定地借鉴意义     

模板工程安全防范研究

基于模板及其支架与混凝土强度未达到设计值的钢筋混凝土结构组成的临时承载体系,分析了模板及其支架应承担的施工荷载,发现以当前设计方法计算的模板及其支架的承载力不能完全抵抗,鉴此,建议了模板及其支架承载力的修正设计方法;为了维持模板及其支架应具备的安全度,以达到安全防范的目的,探讨了必须满足的正常设计、正常安装与拆除、正常使用与监控维护等条件,提出了将模板及其支架设置层数、施工周期、旌工活荷载限值等因素纳入模板及其支架的正常设计以及建立模板及其支架安全防范风险评估体系技术的建议.     

浅谈模板早拆体系在施工中的应用和发展

从工程实际出发，详细阐述了模板早拆体系的早拆原理以及支模、配模和拆模方法，从理论上对楼板混凝土强度进行了验算，并列出了模板早拆体系在施工操作中的技术措施和注意事项，还从模板早拆体系的材料投入、工期安排、混凝土质量和综合经济效益上阐明了模板早拆体系的优点和发展前景。     

Computer simulation of complex-shaped formworks using three-dimensional numerical models

This work describes a three-dimensional numerical model, developed with the ANSYS finite element software package, which simulates the behaviour of fresh concrete and formwork walls to obtain the resulting pressures in complex-shaped formworks. The results obtained with the proposed model highlight the influence of the inclination of a formwork on the lateral pressures exerted on its walls by fresh concrete. The normal pressures on the lower inclined formwork wall were found to be larger than those exerted on the upper inclined wall. In addition, it was also found that normal pressures vary along the formwork wall in the longitudinal direction in a different way depending on the sidewall. The proposed computer model allows examining load distributions in complex-shaped formworks, which is not contemplated in current standards.     

Influence of longitudinal structural connectivity on seismic performance of three-hinged precast arch culverts

The hinge type of precast concrete arch culvert was introduced to Japan from France in the 1990s in consideration of the saving of labor, shortening of the construction period, and high quality control of the concrete members. However, due to the 2011 off the Pacific Coast of Tohoku Earthquake (March 11, 2011), the three-hinged precast arch culverts that had been constructed in Japan at the beginning of the period when precast arch culverts were firstly introduced, suffered damage, which spoiled their serviceability. According to the extent of the damage and the type of culverts that were damaged, the longitudinal structural connectivity of the culverts was assumed to be one of the possible reasons for the reported damage mechanism. Therefore, the objective of this paper was to clarify how strongly the longitudinal structural connectivity influenced the longitudinal seismic behavior of the three-hinged arch culverts. To achieve this objective, an elasto-plastic finite element analysis was conducted with an analytical model that could capture the characteristics of the damaged culverts. Simultaneously, a penalty method with the bi-linear spring model was applied as a solution to the contact-impact problems of the precast segmental arch members. As a result, it was found that the weaker longitudinal structural connectivity in the damaged culverts allowed the torsional displacements of the arch members to induce critical damage to the arch members, namely, edge defects in the arch crown and concrete foundation. The numerical results proved the unignorable influence of the longitudinal structural connection on the possible damage to three-hinged arch culverts.     

清水混凝土施工工艺

结合大唐云冈热电厂工程的具体实例,确定了清水混凝土的工艺目标及工艺要求,从模板的制作、组合、安装介绍了施工中采取的竹胶模板工艺,提出了混凝土的施工要点及局部处理措施,为混凝土工程施工提供了参考。     

浅谈施工中混凝土配合比的控制

混凝土工程是公路桥涵的主体，混凝土质量的稳定与优良性是桥涵质量优良的前提，通过祁临高速公路施工实践中对混凝土理论的认识与应用相结合，进行科学合理的配合比设计，精心反复的试验，严格的进料、生产控制，保证了桥涵混凝土施工中产品质量的优良率和成本的降低。     

混凝土构件疲劳设计规定及相关问题探讨

对比分析了中国公路桥涵设计规范审批稿和混凝土结构设计规范有关混凝土结构疲劳设计的规定 ,按相应规范验算了 1 2根吊车梁、6根预应力混凝土及 2根钢筋混凝土简支 T型梁桥主梁的疲劳承载能力 ;对比分析了吊车梁与桥梁所受荷载的差异以及相应构件压区混凝土和拉区钢筋在应力水平、应力幅、应力比等方面的差异 ,并初步探讨了公路钢筋混凝土桥涵的疲劳问题 ,指出了公路桥涵设计规范在结构疲劳设计方面的不足 ,提出了相关建议