共查询到20条相似文献,搜索用时 234 毫秒
1.
桩基作为深基础,广泛应用于工程建设各领域.但桩基设计及施工往往存在误解,以为桩越长越好.本文分析了桩的荷载传递机理,总结了多个工程桩基测试资料,力求对桩基础设计和施工起到一定的指导作用. 相似文献
2.
用于狭陡沟谷泥石流防治的坝基钢管桩初探——以小岗剑沟泥石流治理工程为例 总被引:1,自引:0,他引:1
以四川绵竹小岗剑泥石流应急治理工程1#拦砂坝的基础设计、施工工艺、泥石流过流运用为依据,探讨了狭陡沟谷重力式拦砂坝钢管桩基础的设计和施工技术。针对狭陡型泥石流沟道的特殊地形及其带来的设计施工方法、材料和设备运输受限的问题,分析了钢管桩基的适用性和有效性,通过结构组成、布置构造和分析方法的创新,探索了复合桩基的实施要点,提出了钢管桩基受力分析的"折算断面法"。1#拦砂坝为重力式板基,下部碎石土持力层设钢管桩群,桩间土压力灌浆构成复合桩基,用于提高地基承载力并阻止坝下冲刷淘蚀。根据2012年汛期过流时坝下沟道剧烈冲刷引起的坝基淘刷与临空状况,进一步探讨了有关钢管桩基础设计优化等问题。 相似文献
3.
随着我国经济的迅猛发展以及城市化进程的不断推进,城市化建设速度变得越来越快。在城市建设中,出现了围湖造地、平山造地等一系列扩张运动,但与此同时也出现了各种地基问题。要想确保地基施工质量与工程质量,必须提升岩土工程地基与桩基础处理技术的水平。基于此,本文先对岩土工程地基与桩基础概念进行了分析,并探讨了岩土工程中地基与桩基础处理技术。 相似文献
4.
5.
6.
7.
《山地学报》2017,(2)
基于舟曲县三眼峪泥石流灾害的实地考察和资料分析,对该地区常见的夯土木构、砖木结构、砖混结构和框架结构4类典型受损的结构形式进行了分析,确定建筑物的破坏模式主要为淤埋破坏和倒塌破坏。对现有的泥石流冲击作用计算公式进行了分类整理,以三眼峪泥石流实测数据为例对比分析整体冲击力和大石块冲击力的不同计算理论和计算结果。为便于工程技术人员进行房屋抗泥石流设计,提出了基于泥石流深度并考虑泥石流动力效应的设计计算方法,给出了以三眼峪泥石流为例的动力影响系数设计值和设计泥石流深度取值范围;并对当地典型夯土木结构房屋进行了泥石流安全性分析。此简化计算方法物理意义清晰,计算快捷有效,可用于泥石流多发地带的设计荷载计算,其关键参数泥石流深度可根据当地常年记录以统计值采用,动力放大值可根据沟床纵比降和沟床糙率系数确定。 相似文献
8.
分析了四川盆地缓倾角红层地质结构特征,将下覆泥岩风化形成凹岩腔后的砂岩视为悬臂岩梁,提出了一种计算泥岩风化凹进极限深度及在设计支撑柱时计算支护力的计算方法,并给出一个计算示例。 相似文献
9.
10.
有年无量历史洪水在设计洪水计算中的应用 总被引:1,自引:1,他引:0
内陆干旱区水文站网稀少,尤其是中小河流,连序、完整的洪水资料比较短缺,设计洪水计算的基本条件难以满足。为提高洪水系列代表性,基本途径是增加洪水系列的信息量。在已往的设计洪水计算中均采用已有连序系列加有年有量历史调查洪水值。但是,在历史洪水调查与考证中,既能查明洪水量级,也能考证出发生年份的历史洪水的资料极少,而只能调查出考证期而查不出洪水值的‘有年无量历史洪水’资料的较多,所以对这部分资料的合理、充分应用,是设计洪水计算中新的问题。本文针对有年无量历史洪水在设计洪水计算中的应用,进行了分析、探讨,其结果认为:采用,能增大对有年无量历史洪水资料的历史洪水信息量,提高洪水系列代表性,合理确定统计参数,提高设计洪水成果精度,对工程设计具有十分重要的作用。 相似文献
11.
A pile foundation is commonly adopted in geotechnical engineering to support structures, and its application has been extended to cold-regions engineering. In past decades, a host of scholars investigated pile behaviors and proposed design guidelines for seasonally frozen ground or permafrost. This paper reviews the research with respect to pile performance and engineering practice in cold regions, organized as follows: (1) creep tests and bearing capacity, (2) frost-jacking hazards, (3) laterally loaded piles, (4) dynamic responses, (5) refreezing due to concrete-hydration heat, and (6) improved countermeasures and design methods. We first summarize previous research and recent progress; then, predict the development trend of pile foundations in cold regions and recommend further research. 相似文献
12.
Piles are the main building foundation in permafrost regions. Thawing the permafrost foundation would have a negative effect on a pile, and may cause damage to the building. This paper focuses on the effects of negative friction force due to the melt of permafrost, and presents four calculated methods for bearing capacity of a pile. An engineering station was taken as an example, where the lengths of a pile were compared based on four methods. Finally, quick field load tests were carried out, and some meaningful conclusions are presented. Thus, these analytical results can be used to design a pile for permafrost regions. 相似文献
13.
14.
To determine the appropriate soft foundation treatment for a river-crossing tunnel, freezing reinforcement design and technology
were introduced based on the channel tunnel design and construction practice. Through finite element analysis and engineering
practices, two rows of horizontal perforated freezing pipes were designed and installed on both sides of a passage for tunnel reinforcement,
which produced the thickness and strength of frozen crust that satisfied the design requirements. These information are
valuable for guiding the design and construction of river-crossing tunnels in coastal areas. 相似文献
15.
软岩高边坡预应力锚索抗滑桩的设计计算 总被引:3,自引:1,他引:3
目前已提出了多种预应力错索抗滑桩的设计计算方法,例如按Winkler弹怀地基梁的方法、错索与桩的协调变形的方法等.由于软弱岩体的变形特征,结构与岩体的相互作用机理较为复杂,这些方法难以直接应用于软岩高边坡工程,需要加以分析改进.应该分析预应力锚索抗滑桩的施工顺序、实际受力条件、锚索预应力的主要控制因素等,分阶段进行计算,这样得出的计算结果才有可能与实际情况一致.在充分吸取现有计算方法优点的基础上,提出了改进的方法.通过实际工程的计算,得出了较为符合实际情况的结果. 相似文献
16.
Mongolia is a land-locked country in Central Asia, located between Russia and China. The country's high altitude results in cold, dry, and harsh climatic conditions with permafrost being widespread through the territory. Although the capital city Ulaanbaatar is situated in an area with discontinuous permafrost, the downtown section has recently seen a disappearance of permafrost due to an underground central heating system. During the last decade, expansion of the suburbs toward the Nalaikh Depression has resulted in construction of a new residential complex (Urgakh Naran), construction materials trading center, cement factory and agricultural products market. In the next 10 years, projects such as a university campus, logistics center, residential complex, railway and highway extensions connecting Russia and China have been planned. Engineering-geological and geotechnical investigations have been conducted for these construction projects. This paper presents some of the results determining the engineering geocryological conditions of Nalaikh district and offers foundation design options. 相似文献
17.
With the development of high-speed railway in China, composite foundation with rigid piles has become a standard solution of meeting the high requirements of stability and post-construction settlement ... 相似文献
18.
Permafrost is found on 63%of the territory of Mongolia. This paper provides evidence that the main influences on per-mafrost formation are meso and micro factors of climate and geographical location. R... 相似文献
19.
珊瑚礁岩土的工程地质特性研究进展 总被引:1,自引:0,他引:1
文章综述了珊瑚礁岩土工程的研究意义、珊瑚礁岩土的组成、钙质砂的物理性质、钙质砂的静力学特性、珊瑚礁岩土中的桩基工程、珊瑚礁混凝土等方面的研究现状。得出:1)颗粒易破碎是钙质砂最重要的特性,直接影响着钙质砂的其他力学性能,而影响钙质砂颗粒破碎的主要因素有围压、有效应力、颗粒级配、初始孔隙比、颗粒强度、颗粒形状等;2)生物颗粒的易破碎以及成桩过程对钙质砂结构的扰动,导致钙质砂中的桩基承载力远低于普通石英砂;3)在以珊瑚砂为原料的混凝土工程中,利用抗硫酸盐水泥拌养的珊瑚混凝土,其强度和耐久性相对较好。最后指出:加强对钙质砂颗粒破碎发生机理的研究以及建立破碎模型、加强对新型珊瑚礁钢筋混凝土和新型桩基的研究、开展珊瑚礁岩土工程的灾害预防与处理以及工程后期的养护等,是珊瑚礁岩土工程进一步研究的方向。 相似文献
20.
在调查分析秦巴山地生态环境因子的基础上,选取地形和坡度为主导因素,进行土地生态环境功能划分,并运用景观生态学、土地经济学有关原理,针对不同功能区生态环境的现状特点,分别总结出土地景观生态环境设计的模式,提出用系统思想指导景观生态环境建设与保护的观点. 相似文献