滨库滨海淤泥质岸坡填土造地新方法研究

发布时间：2018-05-28 05:40

本文选题：填土造地 + 三峡移民　；参考：《重庆交通大学》2015年硕士论文

【摘要】：我国的基础工程建设取得了突飞猛进的发展,在随后的20年左右将迎来前所未有的建设高峰期,滨海滨库地带填土造地逐渐成为滨库滨海地区提高土地资源利用率的重要手段,填土造地所带来的经济、环境、社会影响成为大家关注的焦点,同时三峡蓄水后,移民数量不断增加,高达达113万,移民数量的增加使得土地资源的紧张,人口的迅速增长等更加剧了土地的匮乏。岸坡在天然状态下是稳定的,通过开挖回填再造之后,土体发生扰动,加之在岸坡上部建屋铺路,建筑物的自重加上动荷载作用在岸坡上,则容易发生失稳,损坏上层建筑及影响周围居民正常生活,岸坡失稳必然要对库区城镇居民的生命财产安全造成不同程度的威胁。基于上述研究背景,本文紧密结合宁江岛岸坡回填工程,提出了分区填土技术、滨海滨库填土岸坡与原岸坡有效结合技术、填土与护岸结构同步排水技术三种关键技术,利用Sigma/w模块模拟开挖回填及库水位作用下岸坡应力应变变化规律,并将Slope/w模块和Seep/w模块进行耦合,研究开挖台阶及水位涨落速度与岸坡稳定性之间的关系,主要的工作及研究成果如下:(1)本文通过查阅大量关于造地型岸坡的文献资料,分析其研究现状,总结其不足,提出了填土岸坡与原岸坡相容性概念。填土岸坡与原岸坡的相容性就是指填土体与原岸坡界面的有效的契合,实现无缝连接,增大其相互之间的摩擦力,从而增强岸坡稳定性。(2)本文从填土体与原岸坡的结合形式入手,结合填土体与原岸坡土体性质确定了可能的三个滑动面,并基于此展开后续的模拟工作,通过Slop-w模块确定了最优台阶宽度为2m。(3)基于饱和-非饱和渗流理论,通过Geo-studio模拟软件模拟最优开挖台阶宽度下不同水位涨落速度对宁江岛岸坡的稳定渗流情况,通过模拟结果得到了水位涨落速度与岸坡稳定渗流之间的变化关系:水位上涨速度越快,库水的入渗所产生的孔隙水压力会大大降低岸坡的稳定性。(4)在填土造地工程中,均会涉及填土界面处理、填土的排水及保证稳定性等问题,根据模拟结果分析出来的稳定系数变化规律提出了填土造地防护技术与同步排水技术。本研究提出的滨海滨库地带填土造地的关键技术,能够在填土造地施工技术方面发挥较大作用。
[Abstract]:The construction of basic engineering in our country has made rapid progress, and in the next 20 years or so, it will ushered in an unprecedented peak of construction. The reclamation of land in coastal areas has gradually become an important means to improve the utilization rate of land resources in coastal areas. The economic, environmental and social impacts of land reclamation have become the focus of attention. At the same time, after the three Gorges impoundment, the number of migrants has been increasing, reaching as high as 1.13 million. The increase in the number of migrants has made the land resources tight. Rapid population growth has exacerbated the scarcity of land. The slope is stable in the natural state. After excavation, backfilling and reengineering, the soil is disturbed. In addition, when the upper part of the bank slope is paved, the weight of the building and the dynamic load on the bank slope are liable to destabilize. Damaging superstructure and affecting the normal life of the surrounding residents, slope instability will inevitably pose a threat to the safety of life and property of urban residents in the reservoir area. Based on the above research background, three key technologies are put forward in this paper, which are combined with the backfill project of Ningjiang Island bank slope, the effective combination of coastal bank fill slope and original bank slope, and the simultaneous drainage technology of fill and bank protection structure. The Sigma/w module is used to simulate the stress-strain variation law of bank slope under the action of excavation backfill and reservoir water level, and the Slope/w module and Seep/w module are coupled to study the relationship between excavation step, water level fluctuation speed and slope stability. The main work and research results are as follows: (1) by consulting a large number of documents about land-based bank slope, this paper analyzes its research status, summarizes its deficiency, and puts forward the concept of compatibility between fill bank slope and original bank slope. The compatibility between the fill slope and the original bank slope refers to the effective fit between the fill soil and the original bank slope, to realize the seamless connection and to increase the friction between the fill soil and the original bank slope. So as to enhance the stability of bank slope, this paper starts with the form of combination of fill soil and original bank slope, determines three possible sliding surfaces combined with the properties of filling soil and original bank slope soil, and carries out subsequent simulation work based on this. Based on the saturated-unsaturated seepage theory, the stable seepage flow of Ningjiang island slope under different water level fluctuation velocities under optimal excavation step width is simulated by Geo-studio software based on the Slop-w module. Through the simulation results, the relationship between the fluctuation velocity of water level and the steady seepage flow on the bank slope is obtained: the faster the water level rises, the lower the pore water pressure caused by the infiltration of the reservoir water will greatly reduce the stability of the bank slope. All the problems are related to the treatment of the interface of the fill, the drainage of the fill and the guarantee of the stability. According to the variation law of the stability coefficient analyzed from the simulation results, the technology of land reclamation protection and synchronous drainage are put forward. The key technologies proposed in this study can play an important role in the construction of land reclamation.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU447;P748

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