挤扩支盘桩结构设计对桩基竖向承载性能影响的试验研究

挤扩支盘桩作为一种新型桩基形式,在建设领域有着广阔的应用前景.为研究挤扩支盘桩结构设计的差异性因素对于桩基承载受力及变形性能的影响,建立室内1∶10大比尺挤扩支盘桩物理模型,分别开展了不同盘数的单桩模型、不同桩间距的双桩模型的对比试验研究.研究结果表明,因受相邻桩的相互影响作用,在相同桩顶反力作用下,随着桩间距减小,桩...     

保水剂在路堑边坡水土防治的应用研究

保水剂是一种绿色环保的保水材料,目前研究集中在保水剂与土体相互作用的微观结构方面,对其力学特性方面研究较少。以掺保水剂土体为研究对象,利用保水率试验和直剪试验分别研究不同掺量和含水量土体的保水率和抗剪强度,探寻其保水性能与抗剪强度变化之间的关系。通过分析表明：土体的保水率随保水剂掺量增加而增大,但超过一定掺量后,其增幅较小;土体掺入保水剂后,黏聚力增大,内摩擦角降低,有利于表层土的稳定;塑限是特殊的含水量,接近最优含水量,能使压实土形成最优结构。综合考虑保水性、经济性和抗剪强度,确定在掺量0.3%时形成最优结构。     

乳化沥青对水泥稳定碎石力学性能影响的微观机理研究

乳化沥青水泥稳定碎石的微观结构和宏观特性联系紧密。为进一步研究混合料力学性能的演变规律,文中首先通过扫描电镜(SEM)和X射线能谱分析(EDS)探究其微观形态结构和物相组成,其次通过无侧限抗压试验、弯曲试验和干缩试验,分析乳化沥青对水泥稳定碎石宏观特性的影响,并进一步分析其微观结构组成和形貌特征对宏观性能演变的影响机制。研究表明,乳化沥青破乳行为和水泥水化反应同时进行,产生由沥青薄膜与水泥水化产物交织形成的絮状胶体,并进一步和针状水泥水化晶体骨架结构交织形成复杂致密的空间网络结构,从而降低混合料的无侧限抗压强度,并提高其弯拉能力和收缩变形能力。     

VR技术在铁道车辆教学中的探索与应用

目前,我国铁路事业发展迅猛,铁道车辆专业的教学迎来了新的机遇和挑战.本文首先分析了铁道车辆专业的教学现状,随后分析了VR技术在铁道车辆专业教学中应用的优势和可能遇到的阻碍,肯定了VR技术对于教师教学和学生学习的积极作用.     

多跨连续钢箱梁工程施工测量控制技术

城市立交桥建设经常跨越城市主干道及相关构筑物,为解决施工与交通的矛盾往往采用多跨钢箱梁等结构形式的桥梁。钢箱梁具有安装速度快、施工跨度相对较大的特点,然而钢箱梁整体结构较轻,且往往是分段安装,其安装精度控制要求较高,钢箱梁安装中的测量往往是决定桥梁线形的重要手段。介绍郑州市北三环快速化工程Ⅱ标段工程钢箱梁安装工艺,并对钢箱梁安装的测量控制技术进行分析,为钢箱梁安装工程提供借鉴。     

以责任和担当助力企业复工复产 ——中山公交集团全面夯实疫情防控线

准确把握疫情防控和经济形势变化,因时因势调整工作着力点,中山公交集团一手抓防控,一手抓运营,以责任和担当保障广大市民的出行服务,助力全市企业复工复产。从精细疫情防控到精准投放运力,从线路运营服务到"一站式"定制服务,从保障市民出行到服务复工复产。自战"疫"打响的第一天起,中山市公共交通运输集团有限公司(以下简称:中山公交集团)坚决贯彻落实中央、省、市和上级的部署,率先在全省公交行业启动I级应急响应,以“战时状态”坚决遏制疫晴在公交的传播路径。     

物流园区运作的若干问题及建议

针对物流园区当前发展中存在的问题,从物流园区的功能设计入手,就物流园区的运作提出建议,可为政府决策部门和物流园区经营业主提供参考与帮助.     

公路隧道新奥法粗解

评述了新奥法的概念、特征、围岩类别和划分原则等锚杆、导管、喷射混凝土和围岩形成整体受力结构的情况。     

Comparison between North-South Aid and South-South Cooperation: Based on the analysis of the new development finance institutions

According to the different players, development cooperation is often divided into North-South Aid and South-South Cooperation, both of which have a history of several decades. Since the beginning of the 21st century, the rise of a number of emerging economies has brought South-South Cooperation into a new stage, which can be seen from the establishment of some new development finance institutions led by developing countries. BRICS Bank, Asia Infrastructure Investment Bank (AIIB) and Silk Road Fund are three important new development finance institutions. Compared with the traditional development finance institutions like World Bank and International Monetary Fund (IMF), they have their own concepts of development cooperation, which are different from the traditional ones. First, the new finance institutions pay more attention to the equality between partners, not imposing conditions and respecting the ownership of development partners. Second, the new development finance institutions value the market philosophy, which means that they emphasize the importance of field investigation and implement development cooperation in accordance with the actual needs of the partners and the comparative advantages of the providers. Finally, the new development finance institutions focus their resources on problem-solving and avoid doctrines-imposing. They believe that it is easier for the developing countries to achieve development through a gradual and bottom-up model. Although there are differences between the traditional and new development finance institutions, the latter is not parallel to or substitute of the former. They can cooperate with each other and provide better public goods for international cooperation through inclusive competition.     

预应力连续箱梁桥施工监理程序

从监理角度对如何在预应力连续梁施工中控制好质量,从而使桥梁达到设计和规范要求进行了论述.