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1.
抗滑桩是滑坡整治工程设计中的主要技术措施之一,本文通过对抗滑桩的力学性质和受力状态进行客观分析和评价,提出两种新型抗滑桩结构及其实践应用的可行性,即变截面抗滑桩和推力传递抗滑桩,特别是,推力传递抗滑桩技术,可以节省钢材80%以上,从而大大地降低了抗滑工程造价,并且,从根本上改变了传统的抗滑桩的力学性质和桩身受力状态,值得深入研究、推广和应用。  相似文献   

2.
就目前锚索抗滑桩的研究现状来看,基本上都是将锚索和抗滑桩分开计算,忽略了锚索与抗滑桩之间存在的相互作用关系。针对这一问题,对锚索-抗滑桩-岩土体相互作用系统的计算方法进行了研究。提出了在锚索抗滑桩设计计算中,除了应考虑锚索的强度外。还应该考虑锚索的伸长量,使其与桩的变形相协调。在此基础上,建立了新的锚索抗滑桩计算理论。本文用该方法进行了工程实例分析,并与其他计算方法所得结果进行了对比。  相似文献   

3.
以一维弹性杆理论为基础,简要地叙述了声波测桩的基本原理,分析了应变波在桩身中的传播过程。论述了CE2001工程仪测桩的工作方法及在南昆铁路八渡滑坡抗滑桩检测的应用实例,通过对八渡滑坡抗滑桩的长度、强度及完整性的检测,认为抗滑桩失效的主要原因不是抗滑桩强度,而是桩深不够且多数植于不稳定的强风化岩层中;此外,地震和地质雷达检测出滑坡层面,主要发生在砂岩强风化层上部与松散层底部,进一步说明原抗滑桩为悬浮桩。这为滑坡地带重新构筑抗滑桩设计提供了理论依据。  相似文献   

4.
吴跃刚 《探矿工程》2004,31(5):33-38
通过对襄十高速公路滑坡加固工程的论述,重点介绍了预应力锚索和钢轨抗滑桩技术在滑坡中的成功应用。对预应力锚索、钢轨抗滑桩的设计及施工工艺等进行了探讨。  相似文献   

5.
为评价采用抗滑桩支护后的边坡稳定性,从设计和验算两个角度着手,基于Morgenstern-Price(M-P)法建立了抗滑桩支护边坡的分析模型,进而得到了抗滑桩下滑力和边坡安全系数的表达式;通过引入自适应遗传优化算法,建立边坡稳定性分析优化模型,搜索采用抗滑桩支护边坡的非圆弧最危险滑动面;从确定安全系数求抗滑桩所受下滑力和确定抗滑桩抗力求边坡最小安全系数两种情况出发,探讨了抗滑桩位置对边坡稳定性的影响。结果表明:该方法可搜索出更加符合实际情况的边坡非圆弧最危险滑动面,并且能够得到抗滑桩的下滑力或边坡的最小安全系数,相同条件下抗滑桩应设置在边坡中部较为适合,才能最大发挥抗滑桩的加固作用。  相似文献   

6.
针对传统感测技术存在的问题,本文采用BOTDR分布式光纤感测技术对马家沟滑坡抗滑桩变形进行长期监测分析。在BOTDR监测数据的基础上,对抗滑桩内力进行反演分析,然后与抗滑桩理论设计值进行对比,从抗滑桩内力分布状态及外在环境影响因素两方面对抗滑桩稳定性进行了分析和评价,结果表明:马家沟滑坡在距地表 19m和27 m深度处存在两条滑动面;2015年3月之前,马家沟滑坡整体变形较小,处于相对稳定状态,之后抗滑桩逐渐发挥抗滑作用;目前,抗滑桩剪力已接近设计值,抗滑桩处于不稳定状态,需要加强监测;抗滑桩的变形主要受库水位控制,降雨影响较小。库水位降低时,抗滑桩变形增大,库水位升高时,抗滑桩变形趋于稳定。BOTDR监测技术为长期化、精细化评价抗滑桩稳定性状态提供了十分先进的监测手段。  相似文献   

7.
谭捍华  赵炼恒  李亮  罗强 《岩土力学》2011,32(Z2):190-197
基于强度折减技术和岩土塑性极限分析理论,考虑抗滑桩预加固岩土边坡的加固效应,从功能平衡原理探讨了岩土边坡抗滑桩加固位置、桩长和多抗滑桩共同加固边坡的分析方法。假定机动容许的对数螺旋线速度机构,推导了抗滑桩预加固边坡稳定性安全系数的计算表达式。采用内点迭代方法对安全系数目标函数进行能量耗散最小化意义上的优化计算,算例对比验证了方法和程序的正确性。分析了单抗滑桩加固措施条件下的边坡局部稳定性特性,并由此推导了多抗滑桩加固边坡的稳定性分析算式。研究表明,抗滑桩设置位置改变对边坡安全系数、临界滑裂面位置和桩长均有显著影响,抗滑桩加固边坡的最优设置位置应位于边坡中下部区域  相似文献   

8.
底端嵌固桩与滑体相互作用的物理模型试验研究   总被引:4,自引:2,他引:2  
魏作安  李世海  赵颖 《岩土力学》2009,30(8):2259-2263
抗滑桩与滑坡体的相互作用是一个复杂系统。利用专门设计的安置有光纤和电测器件的物理模型试验装置,通过改变抗滑桩的几何尺寸、布置间距以及滑体的滑移面角等有关参数,研究抗滑桩与滑坡体之间的相互作用,获得了在不同桩体几何尺寸、间距以及滑体滑移面角? 等参数情况下抗滑桩的受力状况和滑体作用在抗滑桩上的滑坡推力函数q(H),进一步揭示了抗滑桩与滑体之间的相互作用机制。  相似文献   

9.
野水沟滑坡为忠县-武汉输气管道工程沿线上的一滑坡灾害点,采取了抗滑桩这一治理措施以保证管道的安全运行。为了确保施工期的安全和获取抗滑桩的内力分布数据并客观评价抗滑桩的工作状态,对滑坡体进行了长期的GPS地表位移和抗滑桩应力监测。通过建立单筋矩形截面受弯构件模型,给出了根据钢筋计监测数据计算抗滑桩弯矩的方法并提出了安全可靠度这一概念以定量判断抗滑桩的工作状态。对该滑坡地表位移及抗滑桩内力监测成果分析表明,抗滑桩目前处于安全状态,发挥了一定作用,治理工程取得了明显效果,抑制了滑坡的进一步变形。   相似文献   

10.
十三陵抽水蓄能电站上池西岸边坡中,存在许多条不同产状和结构的断层,曾发生多次滑坡,构成了对电站上池工程的威胁,因此在池顶采用抗滑桩加固处理边坡。为了解加固后边坡的稳定性和抗滑桩的受力状态及其相互作用,用有限元方法对该岩体边坡进行了稳定性分析。  相似文献   

11.
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.  相似文献   

12.
The Global Stratotype Section and Point (GSSP) for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy (SSS) proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy (ICS). The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob's Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs.  相似文献   

13.
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.  相似文献   

14.
Important tendencies in development of the world mineral-resources sector at the beginning of the 21st century were an increase in production and consumption of mineral materials differentiated by types of metals and nonmetallic mineral raw materials, by countries and regions, as well as the concentration of the production of mineral raw materials in a small number of countries, and a reduction in industrial reserves of minerals in the world economy, even at the current stage of their extraction. These tendencies should be taken into account in working out a strategy for development of the Russian mineral raw-material base.  相似文献   

15.
Taking the example of W Sudan, an analysis of the climatic incidents leading to the two recent famine disasters is made. On this natural background, the human side is investigated. Focus is directed towards the fragile economic structure of the famine-prone population groups. An early-warning system for famine in the Sahelian Zone is proposed taking grain production and storage, livestock development and the relationship between the prices of livestock and grain as major indicators.  相似文献   

16.
东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。  相似文献   

17.
18.
The structure of the eastern Pyrenees consists mainly of south-directed thrusts involving basement and cover rocks. An antiformal stack developed by the piling up of basement thrust sheets which outcrop in the Axial zone. These structures account for a thin-skinned thrust model rather than a vertical fault model in which the Axial zone would be essentially autochthonous, and the North-Pyrenean fault the axial plane of a fan thrust system. New data from the Eastern Pyrenees and the thin-skinned model suggest that(1) the structure east of the Pedraforca nappe is similar to that of the Central Pyrenees; (2) the cover rocks of the South-Pyrenean units and of the Axial zone-after restoration—built up a northwards-thickening prism consistent with the existence of a unique Pyrenean sedimentary basin during Mesozoic time; (3) the Axial zone is only a complex antiformal stack developed as a part of South-Pyrenean system related to the Paleogene thrusting-tectonics. The Axial zone palaeogeographic area had no special meaning during Mesozoic time.  相似文献   

19.
20.
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.  相似文献   

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