共查询到20条相似文献，搜索用时 353 毫秒
1.
斜坡上的建筑基础通常需要考虑其稳定性,由于邻近基坑开挖引起斜坡的任何变化都必将影响其上建筑基础的稳定安全。结合重庆市石板坡长江大桥南桥头F匝道桥下基坑开挖过程,采用传递系数法分析研究了基坑开挖、车辆离心力及桩基抗滑力对于斜坡安全系数的影响,为匝道桥的安全提供判断标准。 相似文献
2.
为研究强降雨条件下地表径流和裂隙水流的拖曳力作用对斜坡稳定性的影响,建立斜坡地表径流和地下水渗流耦合分析模型。采用Navier-Stokes方程描述地表径流和裂隙水流,Brinkman-extended Darcy方程描述土体和岩石中的渗流,并根据不同介质交界面处流速相等及剪应力连续的边界条件,推求各介质中的流速分布。应用Newton内摩擦定律求得水流对斜坡产生的拖曳力,进而将拖曳力嵌入刚体极限平衡理论对斜坡稳定性进行分析。典型斜坡实例计算结果表明,当未考虑拖曳力效应时,斜坡的安全系数为1.164,考虑水流对斜坡土体产生拖曳力效应时,斜坡的安全系数为1.089,斜坡安全系数降低了6.44%。这表明拖曳力作用对斜坡的稳定性存在不利影响,斜坡土体在近乎临界稳定状态下拖曳力将对斜坡失稳起到决定性作用。最后分别讨论了考虑拖曳力和不考虑拖曳力情况下斜坡的安全系数与径流水深、斜坡倾角、土层厚度之间的关系。分析表明,在其他条件相似的条件下,斜坡越陡,斜坡土体的安全系数下降越明显;斜坡安全系数随着斜坡倾角增加而不断降低,随着土层厚度的增加而不断降低。 相似文献
3.
《岩土力学》2020,(2)
为研究强降雨条件下地表径流和裂隙水流的拖曳力作用对斜坡稳定性的影响,建立斜坡地表径流和地下水渗流耦合分析模型。采用Navier–Stokes方程描述地表径流和裂隙水流,Brinkman-extended Darcy方程描述土体和岩石中的渗流,并根据不同介质交界面处流速相等及剪应力连续的边界条件,推求各个介质中的流速分布。应用Newton内摩擦定律求得水流对斜坡产生的拖曳力,进而将拖曳力嵌入刚体极限平衡理论对斜坡稳定性进行分析。典型斜坡实例计算结果表明,当未考虑拖曳力效应时,斜坡的安全系数为1.164,考虑水流对斜坡土体产生拖曳力效应时,斜坡的安全系数为1.089,斜坡安全系数降低了6.44%。这表明拖曳力作用对斜坡的稳定性存在不利影响,斜坡土体在近乎临界稳定状态下拖曳力将对斜坡失稳起到决定性作用。最后分别讨论了考虑拖曳力和不考虑拖曳力情况下斜坡的安全系数与径流水深、斜坡倾角、土层厚度之间的关系。 相似文献
4.
《岩土力学》2021,(2)
为研究强降雨条件下地表径流和裂隙水流的拖曳力作用对斜坡稳定性的影响,建立斜坡地表径流和地下水渗流耦合分析模型。采用Navier–Stokes方程描述地表径流和裂隙水流,Brinkman-extended Darcy方程描述土体和岩石中的渗流,并根据不同介质交界面处流速相等及剪应力连续的边界条件,推求各个介质中的流速分布。应用Newton内摩擦定律求得水流对斜坡产生的拖曳力,进而将拖曳力嵌入刚体极限平衡理论对斜坡稳定性进行分析。典型斜坡实例计算结果表明,当未考虑拖曳力效应时,斜坡的安全系数为1.164,考虑水流对斜坡土体产生拖曳力效应时,斜坡的安全系数为1.089,斜坡安全系数降低了6.44%。这表明拖曳力作用对斜坡的稳定性存在不利影响,斜坡土体在近乎临界稳定状态下拖曳力将对斜坡失稳起到决定性作用。最后分别讨论了考虑拖曳力和不考虑拖曳力情况下斜坡的安全系数与径流水深、斜坡倾角、土层厚度之间的关系。 相似文献
5.
由于历史上开采铁矿的弃渣及城市垃圾的无序堆放，在燕翅山周边形成人工堆积斜坡，直接威胁着其附近居民和单位安全，同时影响着周边的进一步开发建设。通过地质灾害勘查，分析影响人工堆积斜坡稳定性的因素，建立人工堆积斜坡的概化模型，采用传递系数法进行了稳定性定量评价，评价结果表明燕翅山多个渣石堆斜坡整体稳定。但是，由于渣石堆物质成分混杂，存在不均匀沉陷、斜坡前缘地面裂缝和坍塌。为此，提出了针对人工堆积斜坡的不同部位采取削坡、护坡、修建挡土墙及建立排水设施等措施，不仅为燕翅山渣石堆斜坡综合治理指明了方向，也对今后其周边的开发建设及可持续发展提供了依据。 相似文献
6.
论述了施工企业建设现代安全生产管理体系的重要性,并总结了广东煤炭地质局建设安全生产管理体系．促进安全生产的实践经验,提出了施工企业应从以建立完善安全生产责任制为核心,健全各项规章制度．加强员工的教育培训、资金投入和安全检查五个方面为重点建立现代安全生产管理体系的思路。 相似文献
7.
斜坡系统可靠性分析研究 总被引：3，自引：0，他引：3
:斜坡系统是一个多变的、随机的、具有多种不确定性的复杂系统 ,因此在斜坡稳定性研究中引入可靠性理论意义重大且应用前景广阔。文中从单体斜坡系统和区域斜坡系统两个方面 ,论述了斜坡系统可靠性分析的研究现状和发展趋势。单体斜坡系统可靠性研究的主要方向是 :影响因素与评价模型的进一步研究 ,初步建立可靠指标与安全系数相结合的斜坡稳定性二元指标体系。区域斜坡系统可靠性研究的主要方向是 :利用具有普适意义的可靠性指标 ,结合地理信息系统 (GIS)进行斜坡稳定性研究 ,初步建立风险评价和风险管理的斜坡安全体系 相似文献
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9.
地震载荷是影响复杂结构斜坡塌滑的一个重要因素。本文以汶川震区一边坡为实例,利用有限差分法FLAC-3D对地震动力下斜坡进行了数值模拟。并且在用FLAC-3D进行斜坡动力分析时探讨了边界条件设置、动力时程的合成以及输入和转化。从位移场与速度场进行了详细的动力分析,获得该斜坡地震载荷下位移场、速度场的变化规律,指出山体斜坡在非连续介质状态下软弱面区域位移和速度最大,为后续进行复杂的山体破坏力学研究提供理论依据。 相似文献
10.
探讨降雨入渗作用对人工填土斜坡稳定性的影响,能为避免降雨诱发滑坡提供一定的理论依据。本文以贵州省定东小学填土-坡积土斜坡为例,在分析人工斜坡体工程地质特征的基础上,利用有限元Geostudio软件多模块的耦合,分析了不同降雨条件斜坡的渗透场、应变场特征和稳定性,同时分析了前期与后期降雨和填土前后的稳定性。结果表明：人工填土斜坡体的地下水流速和最大剪应变均集中于填土与坡积土界面附近,且随降雨强度增加而增加;降雨强度和降雨持续时间与斜坡稳定性呈反比;填土因素一定程度上增强了降雨渗透对斜坡稳定性的影响,填土￣坡积土界面为人工填土斜坡失稳的最大潜在滑动面;降雨前期对斜坡稳定性影响大于后期,且该效应随降雨强度降低而增强;降雨渗透是通过增加孔压、降低基质吸力、地下水流速增加引起剪应变增加等方式降低人工填土斜坡的稳定性。 相似文献
11.
受特殊的丘陵地形、强风化岩石以及季节性强降雨的影响, 香港滑坡时有发生。根据香港土木工程拓展署(CEDD)土力工程处(Geotechnical Engineering Office, GEO)的相关资料, 梳理了香港工程边坡防治进展的历史进程和关键防治技术, 对我国大陆相关工程边坡防治具有一定的参考价值。 相似文献
12.
香港地区边坡防护与治理 总被引：1，自引：0，他引：1
自开埠以来香港地区边坡事故一直不断。香港政府多年来积极进行边坡的防护治理,成效显著。讨论了香港地区岩土边坡破坏的主要原因、防治滑坡的工程措施及边坡管理系统。香港的边坡防治经验值得内地借鉴。 相似文献
13.
Louis Augustin-Jean 《GeoJournal》2005,62(1):1-13
This paper shows the importance that urban planning plays in the development of Hong Kong. This leads to a reassessment of the role of the government, which is the sole proprietor of the land, in the economy – while it acknowledges the importance of market forces. The first part shows how, since 1945, Hong Kong authorities have been obliged to intervene more in urban planning and local development, despite their liberal ideology. The second part focuses on the interaction between government action and market forces, and their influence in this development. The third part deals with the question of the economic integration between Hong Kong and the Pearl River Delta (PRD) after China started its economics reforms in 1978. The deconcentration of Hong Kong industries to China was mainly due to market forces, but provided a new role for the government. This role is analyzed through its transportation policy – the domain with the most visible governmental intervention before and after 1997. It indicates the preference of the government to develop the territory rather than better integration with the PRD, because of the internal economic problems that may emerge from this integration. Nevertheless, for political and economic reasons, this integration is also seen as necessary. The future of Hong Kong’s economy lies in the answers the authorities will give to this dilemma. 相似文献
14.
This paper shows the importance that urban planning plays in the development of Hong Kong. This leads to a reassessment of the role of the government, which is the sole proprietor of the land, in the economy – while it acknowledges the importance of market forces. The first part shows how, since 1945, Hong Kong authorities have been obliged to intervene more in urban planning and local development, despite their liberal ideology. The second part focuses on the interaction between government action and market forces, and their influence in this development. The third part deals with the question of the economic integration between Hong Kong and the Pearl River Delta (PRD) after China started its economics reforms in 1978. The deconcentration of Hong Kong industries to China was mainly due to market forces, but provided a new role for the government. This role is analyzed through its transportation policy – the domain with the most visible governmental intervention before and after 1997. It indicates the preference of the government to develop the territory rather than better integration with the PRD, because of the internal economic problems that may emerge from this integration. Nevertheless, for political and economic reasons, this integration is also seen as necessary. The future of Hong Kong’s economy lies in the answers the authorities will give to this dilemma. 相似文献
15.
Confined groundwater near the rockhead in igneous rocks in the Mid-Levels area, Hong Kong, China 总被引：1，自引：0，他引：1
It is customary in Hong Kong to assume that the hydraulic conductivity of weathered igneous rocks decreases with depth or as the rock mass becomes less weathered. Such a hydraulic conductivity pattern can only lead to an unconfined aquifer. This paper presents a case study in the regions in and around the Mid-Levels area in Hong Kong regarding a possible relatively high hydraulic conductivity (K) zone and confined groundwater along the rockhead. The Mid-Levels area is located at the lower part of the north-facing slopes of Victoria Peak on Hong Kong Island and is prone to landslides. Although this site has a long history of geotechnical studies because of extensive urban development along the coast and public concern on slope stability, hydrogeology of the site remains poorly understood. This paper reexamined the hydraulic conductivity data in 7 boreholes conducted in the 1970s and found that 4 of them indicate an increase in K at the rockhead. Groundwater conditions revealed by tunnel construction at the coast suggest that K close to the rockhead is about 10 times greater than above rockhead. A careful analysis of storm response of a piezometer group with tips in different depths indicates that there was an upward flow from the bedrock to the colluvium. A field study of two overflow standpipes conducted by the authors showed that the water level can be 0.64 and 3.73 m above the ground surface, which illustrates that the deep groundwater is significantly artesian. A search of the archived site investigation reports from the government and private companies has led to an identification of about 24 sites with overflow boreholes, which suggests that overflow phenomenon is quite common in the study area. The paper then concludes that in the study area there is a relatively high K zone along the rockhead and the groundwater in the zone is confined. It is recommended that geotechnical engineers should carry out a more careful field study on an overflow borehole because such a borehole indicates a confined groundwater condition important for slope stability study and foundation design. 相似文献
16.
Assessment of landslide susceptibility on the natural terrain of Lantau Island, Hong Kong 总被引：33，自引：1，他引：33
Steep terrain and the high frequency of tropical rainstorms make landslide occurrence on natural terrain a common phenomenon
in Hong Kong. For example, more than 800 slope failures were triggered by a rainstorm in November 1993 on Lantau Island, Hong
Kong. Maps of recent landslides interpreted from aerial photographs, in combination with a geographical information system,
were used to evaluate the frequency and distribution of landslides, with particular reference to such physical parameters
as lithology, slope gradient, slope aspect, elevation, vegetation cover, and proximity to drainage line, all of which are
considered to be influential in the occurrence of landslides. A stepwise logistic regression model was obtained between landslide
susceptibility and the above mentioned physical parameters. The study area has been classified into five classes of relative
landslide susceptibility, namely, very low, low, moderate, high, and very high, based on this methodology.
Received: 17 December 1999 · Accepted: 21 March 2000 相似文献
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18.
地质旅游利用现有的地质资源，以一种崭新的角度去发展可持续性的旅游景点。香港地少人多，发展旅游吸引点是极度困难的。香港陆地约有30％为花岗岩覆盖，其中的一半已在城市之下，其余的则拥有相当吸引人的地质景象，有极大潜力发展地质旅游。除吸引地质生态有关游客外，在花岗岩地区开发地质旅游，更容易普及地球科学，同时增强公众对地质地貌之欣赏能力，提高环保及地质保护意识。不过，于香港花岗岩区发展地质旅游所遇到的困难亦不少，主要来自规划、行政及安全的问题，当中需要政府、地区民众及地质旅游工作者并肩合作，寻求最佳解决方法。 相似文献
19.
Shallow slope failure due to heavy rainfall during rainstorm and typhoon is common in mountain areas. Among the models used
for analyzing the slope stability, the rainwater infiltration model integrated with slope stability model can be an effective
way to evaluate the stability of slopes during rainstorm. This paper will propose an integrated Green–Ampt infiltration model
and infinite slope stability model for the analysis of shallow type slope failure. To verify the suitability of the proposed
model, seven landslide cases occurred in Italy and Hong Kong are adopted in this paper. The results indicate that the proposed
model can be used to distinguish failed and not-yet failed slopes. In addition, the proposed model can be used as the first
approximation for estimating the occurrence time of a rainfall-induced shallow landslide and its depth of sliding. 相似文献
20.
珠江口伶仃洋两岸5000年来沉积差异显著。西岸沉积了数千平方公里的三角洲平原,却失去了所有深水良港;而东岸的香港海岸,则长期处于侵蚀状态,保留了曲折的海岸和陡峻的水下岸坡,形成众多的深水港湾。以上差异对香港城市发展有深远影响。文章提出城港关系演变的3个阶段。香港高度发达的商业中心和现代化港口的各种功能系统在最狭小的空间里交叠在一起,带来城市发展的一系列问题。最后对今后50年香港城市发展进行情景分析。从持续发展的角度,指出计划的大屿山新港址有严重的策略选择问题。提出未来香港都市向大屿山东北扩展的策略选择。 相似文献