【作者】 刘志凯；

【导师】 郑毅；

【作者基本信息】 吉林大学 ， 岩土工程， 2005， 硕士

【摘要】 土钉墙作为一种新型的挡土结构,目前在基坑工程中得到了较为广泛的应用,然而对土钉墙在施工过程中的工作性能的理论研究却远远落后于工程实践。土钉墙的稳定分析是土钉墙工程设计中一项极其重要的内容,是土钉墙应用的理论基础。多年来国内外的有关学者就此已开展了大量的研究,提出了一些颇有价值的土钉墙稳定分析方法。总的来说,根据分析的基本原理,这些分析方法可归纳为极限平衡方法、离散单元法和有限元方法三类,极限平衡方法所具有的优点是,原理简单,容易理解、掌握和计算,能保证一定的精度,比有限元方法用得要普遍,深受工程界的欢迎,但是计算结果偏于保守。由于该支护技术涉及到钉土相互作用、群钉效应、土供效应、应力路径问题,因此其机理较刚性的被动支护技术复杂,对大多数问题很难用解析方法解决。例如面层上土压力的大小问题、潜在滑移面的问题、支护结构的变形问题、土钉有效长度的确定、土钉最佳间距的确定等。而以上问题用有限元方法都得到了不同程度得解决。根据北京商务中心地区的工程地质条件以及结合工程实例,并且通过两种不同有限元软件的数值模拟得出了此地区不同于规程的滑移面,在此基础上得出了一种适合此滑移面的设计方案,此方案通过两个工程的实际操作不但安全而且经济效益非常好。更多还原

【Abstract】 soil nailing ,Claim soil nail technology , soil nail structure , reinforcingbar insert muscle soil , gush out stock technology ,etc. too, with have ,rectangular material of high strength that rule assign such as metal pole ,etc.,strengthen a kind of new technology of the normal position soil body; Itmake soil body that strengthen , put in soil soil nailing , panel of the body ofstrengthening, and such parts as certain water drainage structure ,etc.,forming nature and different composite type of normal position soiltemporarily together or permanent soil retaining wall, is it support Hangzhousoil pressure and other strength that come under wall to so as , restrain stress ,soil of body from release and restrain soil from to be body out of shape, thusstrengthen and excavate the base hole or domatic stability, this soil retainingwall is called the soil and nailed the wall. Generally speaking , it is a kind ofnew-type ground treatment technology developed synthetically from thefoundation firm and with two kinds of technology of muscle soil of theanchor to nail technology in the land .Soil is it is it is it is it have certain sand , powder soil , plastic clay of theabove of viscidity to suited to especially to protect to prop up to nail, buteven there is some moulding the viscidity soil layer softly , may adopt thesoil to be nailed and propped up protecting after taking certain measure. Sosoil nail wall is it is it suitable for soil layer situation of Beijing relativelygenerally to protect to prop up , because commercial centre district suitable inBeijing.Have three kinds of ways to nail and prop up the research which protectsthe structure to the soil at present, namely experimental study , theoryanalysis and numerical simulation are studied. Influence soil is it is it protectfactor of mechanism complicated and various , so experimental study soil is itis it protect technical research occupy the main status to prop up to nail atpresent to prop up to nail. A lot of theories analyse the models got and someresults all prove , improve through experimental study, calculate soil is it is itprotect to when shifting , set up on the basis of result of the test live of fullsize wall all nearly structure to prop up to nail especially. So, theexperimental study that the soil is nailed is to understand that nails and propsup and protects the link with extremely important mechanism in the land .Study soil nail test , function of mechanism can divide into room cut test , atodds with the community or the leadership model test and resisting to drawtesting live outdoors direct , the full size wall is tested at present.. Restrictedby the economic condition , very few in the at odds with the community orthe leadership model test and research work of testing the respect of the fullsize wall, have research of in this respect meet all to documents at home atpresent, launch room is it test to shear mostly , model wall test and soil ofscene nail and resist and draw the research work of testing.Soil is it is it protect it is one flexibility initiative restriction mechanismthat is it protect technology , through insert muscle (soil nail ) is it is itexcavate surface nearby soil body intensity to near to improve it to prop up toprop up to nail, thus achieve the goal of propping up and protecting . Shouldis it protect technology is it nail soil interaction , group nail effect , soilsupport the effect , stress route issue to involve to prop up, so mechanism itshard to is it protect technology to be complicated to prop up passively, tomost problem being very difficult with analyze method solve. Such as allkinds of problem of the soil pressure on each, potential to split Taxi question ,is it protect deformation issue , soil of structure nail effective sureness , soilof length nail best sureness of interval ,etc. to prop up while being slippery.And these questions are questions cared about most of engineers, these issuesnail and prop up the optimization design which protect the structure to thesoil with playing a decisive role steadily. The law of finite element is themost frequently used , ripest kind of number value analytical method in rocksoil project question, prop up in protecting in dark base hole, finite elementanalyse often soil body and is it partial to the body as the plasmodium to propup. Soil body under analysing that excavates the condition of unloading andpropping up the stress and displacement which protect body each point, soand design the computing technology to compare in routine, the law of finiteelement is a kind of more accurate , suitability is wide , more rational designcomputing technology. Except that can analyse on the whole that prop up thestress that protects the structure and body of soil around and displacementproperties it, can also be suitable for calculating in dynamic simulation , notonly but also also offer for construction management of the informationfeedback and deal with the means in good time in order to design comparingwith the scheme in advance. In principle, the problem existing can all besolved in various degree in finite element method in the routine designmethod.Finite element it is geotechnological to analyse already very general forlaw to used in, have different views to his validity, the main difficulty amongthem lies in choosing the suitable calculation model and inputting theparameter. To the parameter situation of the finite element, so we chooseANSYS finite element software, consider this finite element parameterchoose less too simple , general routine is it can accomplish to test in beinggeotechnological mainly. Drueker-Prager plays plasticity a literarycomposition model is propose and suitable for a literary composition modelof ball plasticity of the rock soil material first, it is set up on the basis ofconsidering broad sense Mises of quiet water pressure strength surrenderscriterion or Drucker-Prager and surrenders criterion . Its greatest advantagelies in adopting the simple method to consider the influence on the intensityof surrendering of quiet water pressure strength , and there is few modelparameter, it is simple to calculate. At the same time this model consideredcutting bloated and dilatation of the rock soil material . So it is one of themodels that is often adopted in the rock soil project. The test shows , soilbody cut getting bloated to exert a tremendous influence to function that soilnail, so with be able to reflect soil body cut getting bloated to play plasticitycopies of literary composition model with Drueker-Prager of dilatation copiesof selected works.Analyse through the design and construction practice of nailing wall ofhole soil of commercial base of centre district in Beijing and numericalsimulation of using two kinds of finite element software go on, in addition,the deformation monitoring result that the opposite side slope carries ondraws the following conclusion in the construction course:1, Prop up and protect the base hole of the building in the area withmore complicated soil layer, and excavate the depth over 14 meters ofsituations in the base hole , can select for use soil nail wall is it is it protect toprop up to go on , and for being optimum to prop up scheme of partial toing.2, Can know in this kind of soil layer area through two kinds of finiteelement software simulation results, soil nail wall slippery to move surfacecircular among viscidity soil , the straight line shape of the sand, whether soilits nail length assign principle. Dark base hole soil of " protect both sides especially ,the middle can let go of " is it prop up design principle of partial toing to nail. Namelysoil is it is it is it should pay attention to base upper and lower both sides of slope by thehole to protect to prop up to nail, should extend soil nail , encrypt soil not to nail in top;The underpart reduces the length that the soil is nailed, encrypt the density that the soil isnailed. In middle part, base of hole, can according to slippery to move Taxi seat confirmthe length nailed in land. So we design the second set of schemes on the basis of thistheory.3, The software goes on the slope and stability are analysed andmonitored the slope is unanimous basically in displacement with Plais, statethis slope and stability to nailing the wall in the land of software and analyse更多还原