ImageVerifierCode 换一换
格式:DOCX , 页数:16 ,大小:331.67KB ,
资源ID:5850794      下载积分:10 金币
验证码下载
登录下载
邮箱/手机:
验证码: 获取验证码
温馨提示:
支付成功后,系统会自动生成账号(用户名为邮箱或者手机号,密码是验证码),方便下次登录下载和查询订单;
特别说明:
请自助下载,系统不会自动发送文件的哦; 如果您已付费,想二次下载,请登录后访问:我的下载记录
支付方式: 支付宝    微信支付   
验证码:   换一换

开通VIP
 

温馨提示:由于个人手机设置不同,如果发现不能下载,请复制以下地址【https://www.zixin.com.cn/docdown/5850794.html】到电脑端继续下载(重复下载【60天内】不扣币)。

已注册用户请登录:
账号:
密码:
验证码:   换一换
  忘记密码?
三方登录: 微信登录   QQ登录  
声明  |  会员权益     获赠5币     写作写作

1、填表:    下载求助     留言反馈    退款申请
2、咨信平台为文档C2C交易模式,即用户上传的文档直接被用户下载,收益归上传人(含作者)所有;本站仅是提供信息存储空间和展示预览,仅对用户上传内容的表现方式做保护处理,对上载内容不做任何修改或编辑。所展示的作品文档包括内容和图片全部来源于网络用户和作者上传投稿,我们不确定上传用户享有完全著作权,根据《信息网络传播权保护条例》,如果侵犯了您的版权、权益或隐私,请联系我们,核实后会尽快下架及时删除,并可随时和客服了解处理情况,尊重保护知识产权我们共同努力。
3、文档的总页数、文档格式和文档大小以系统显示为准(内容中显示的页数不一定正确),网站客服只以系统显示的页数、文件格式、文档大小作为仲裁依据,个别因单元格分列造成显示页码不一将协商解决,平台无法对文档的真实性、完整性、权威性、准确性、专业性及其观点立场做任何保证或承诺,下载前须认真查看,确认无误后再购买,务必慎重购买;若有违法违纪将进行移交司法处理,若涉侵权平台将进行基本处罚并下架。
4、本站所有内容均由用户上传,付费前请自行鉴别,如您付费,意味着您已接受本站规则且自行承担风险,本站不进行额外附加服务,虚拟产品一经售出概不退款(未进行购买下载可退充值款),文档一经付费(服务费)、不意味着购买了该文档的版权,仅供个人/单位学习、研究之用,不得用于商业用途,未经授权,严禁复制、发行、汇编、翻译或者网络传播等,侵权必究。
5、如你看到网页展示的文档有www.zixin.com.cn水印,是因预览和防盗链等技术需要对页面进行转换压缩成图而已,我们并不对上传的文档进行任何编辑或修改,文档下载后都不会有水印标识(原文档上传前个别存留的除外),下载后原文更清晰;试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓;PPT和DOC文档可被视为“模板”,允许上传人保留章节、目录结构的情况下删减部份的内容;PDF文档不管是原文档转换或图片扫描而得,本站不作要求视为允许,下载前自行私信或留言给上传者【xrp****65】。
6、本文档所展示的图片、画像、字体、音乐的版权可能需版权方额外授权,请谨慎使用;网站提供的党政主题相关内容(国旗、国徽、党徽--等)目的在于配合国家政策宣传,仅限个人学习分享使用,禁止用于任何广告和商用目的。
7、本文档遇到问题,请及时私信或留言给本站上传会员【xrp****65】,需本站解决可联系【 微信客服】、【 QQ客服】,若有其他问题请点击或扫码反馈【 服务填表】;文档侵犯商业秘密、侵犯著作权、侵犯人身权等,请点击“【 版权申诉】”(推荐),意见反馈和侵权处理邮箱:1219186828@qq.com;也可以拔打客服电话:4008-655-100;投诉/维权电话:4009-655-100。

注意事项

本文(土木工程毕业设计翻译.docx)为本站上传会员【xrp****65】主动上传,咨信网仅是提供信息存储空间和展示预览,仅对用户上传内容的表现方式做保护处理,对上载内容不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知咨信网(发送邮件至1219186828@qq.com、拔打电话4008-655-100或【 微信客服】、【 QQ客服】),核实后会尽快下架及时删除,并可随时和客服了解处理情况,尊重保护知识产权我们共同努力。
温馨提示:如果因为网速或其他原因下载失败请重新下载,重复下载【60天内】不扣币。 服务填表

土木工程毕业设计翻译.docx

1、指导教师评定成绩(五级制):指导教师签字:附件C:译文 Numerical Study of Effect of Encasement on Stone Column Performance护壁效应对“碎石桩性能”的数值分析Majid Khabbazian, Stud. M. ASCEGraduate Student and GSI Fellow, Dept. of Civil and Environmental Engineering, 301 DuPont Hall,University of Delaware, Newark, DE 19716. E-mail: majidudel.ed

2、u纽瓦克,DE的19716,特拉华大学,301杜邦厅部,土木与环境工程系,研究生和GSI研究员Majid Khabbazian, Stud. M. ASCE。电子邮箱:majidudel.eduChristopher L. Meehan, A. M. ASCEAssistant Professor, Dept. of Civil and Environmental Engineering, 301 DuPont Hall, University ofDelaware, Newark, DE 19716. E-mail: cmeehanudel.edu纽瓦克,DE.的19716,美国特拉华州,大

3、学部,301杜邦厅,土木及环境工程系,cmeehanudel.eduVictor N. Kaliakin, M. ASCEAssociate Professor, Dept. of Civil and Environmental Engineering, 301 DuPont Hall, University ofDelaware, Newark, DE 19716. E-mail: kaliakinudel.edu纽瓦克,DE的19716,美国特拉华州,大学部,301杜邦厅,土木及环境工程系,副教授。电子邮箱:kaliakinudel.eduABSTRACT摘要Encasing a ston

4、e column with a high-strength geosynthetic provides the columnmaterial with significant lateral confinement, which prevents lateral displacement ofthe column into potentially soft surrounding soil and consequently increases thebearing capacity of the column. Although this technique has been successf

5、ullyapplied in practice, the load transfer mechanism of encased stone columns and theirperformance in comparison with conventional stone columns have not been studied indetail. This paper describes three-dimensional finite element analyses that werecarried out to simulate the behavior of a single st

6、one column with and withoutencasement in a very soft clay soil using the computer program ABAQUS. A comprehensive study was performed to better understand the mechanism of load transfer in conventional stone columns and geosynthetic encased stone columns. The performance of partially encased columns

7、 was then compared to that of fully encased columns and conventional stone columns. 用高强度土工合成材料包裹碎石柱,土工合成材料为碎石柱材料提供显著的横向约束,这样可以防止柱向着周围的软土地基发生侧向位移,从而增加柱子的承载能力。虽然这一技术已成功应用于实践中,受护壁作用的碎石桩的荷载传导机制和性能与传统的碎石桩相比,并没有被详细研究透。本文介绍在一个非常松软的粘土地基上使用ABAQUS软件的计算机程序模拟单个碎石桩,采用三位有限元分析法分析其有无包装效应。为了更深层次的了解传统的碎石桩和被土工合成材料包裹的碎

8、石桩中的荷载传导机制,我们展开了更加全面的研究。在研究中,用部分被土工合成材料包裹的碎石桩分别与完全被包裹的碎石桩和传统的碎石桩进行比较。INTRODUCTION说明Stone columns have been increasingly used for ground improvement, especially forstructures that can tolerate some settlement such as road embankments, storage tanks,low-rise buildings, lightly loaded foundations, etc.

9、 This form of ground improvement is also commonly referred to as granular piles. Extensive use of stone columns is attributed to their proven successes in increasing bearing capacity, reducing total and differential settlements, increasing the time rate of settlement, and reducing the liquefaction p

10、otential of sands. 碎石桩已经被越来越多的用于地基的改善工程,特别是能承受一些沉降的结构,例如,公路路堤、存储仓库、低层建筑以及受到较轻荷载的基础等。这种地基的改良形式也通常被称为碎石桩。碎石柱的广泛使用,是因为它成功地证明了自身在提高承载能力,降低整体沉降和不均匀沉降,增加沉降的时间速率,减少砂土地基液化可能性方面的能力。Stone columns under compressive loads experience failure modes such as bulging(Hughes et al. 1975), general shear failure (Madha

11、v and Vitkar 1978), and sliding(Aboshi et al. 1979). However, in soft clays the most common failure mode for stone columns is bulging (Madhav and Miura 1994). 碎石桩在压力作用下,会产生一些破坏模式,如膨胀破坏模式 (Hughes等人。1975年),一般的剪切破坏(Madhav和Vitkar 1978年),滑移破坏(Aboshi 等人 1979)。然而,在软土地基中,碎石桩最常见的破坏模式是膨胀破坏(Madhav和Miura1994年)。

12、In very soft soils, due to the lack of required lateral confining pressure, the use ofstone columns can be problematic. In these situations, to provide the required lateral confining pressure and to increase the bearing capacity, stone columns are encased by a suitable geosynthetic. Using a high-str

13、ength geosynthetic for confinement not only increases the strength of a stone column, but also prevents lateral displacement of the column into the very soft surrounding soil. Sharma et al. (2004) conducted tests to investigate the effect of geogrid reinforcement on bulging and load-carrying capacit

14、y of a single stone column in soft clay. Murugesan and Rajagopal (2006, 2007) performed model tests and numerical analyses to study the behavior of a single geosynthetic-encased stone column with a limited zone of soil influence (a tributary approach to column group behavior). In the numerical analy

15、ses, Murugesan andRajagopal (2006) performed axisymmetric analyses and assumed continuum elementsfor the geosynthetic without considering the behavior of the interface betweendifferent materials (this paper addresses this phenomenon by using interface elementsin the numerical model). Lee et al. Lee

16、et al. (2007) investigated the failure mechanism and load carrying capacity of individual geogrid encased stone columns by model tests. Alexiew et al. (2005) described the design principles, technologies, and procedures for geotextile encased stone columns and emphasized the importance of the tensil

17、e modulus of the geotextile that is used for column confinement. 在非常松软的软土地基上,由于所需的侧向围压不足,碎石桩的使用可能会出现问题。在这种情况下,给碎石桩包裹一层适当的土工合成材料,可以提供必要的侧向围压,提高碎石桩的承载能力。使用一种高强度土工合成材料,不但可以增加了碎石桩的强度,而且还可以防止碎石桩向着周围松软地基发生侧向位移。Sharma等人(2004)进行测试,以探讨软土地基上的单一碎石桩的膨胀和承重能力对土工格栅的加固效果。 Murugesan和Rajagopal(2006年,2007年) 进行模型试验和数值分

18、析,以研究在一个限定区域内的单个被土工合成材料包裹的碎石桩的性能影响(研究群桩效应的其他途径)。在数值分析的时候,Murugesan 和Rajagopal(2006)进行轴对称分析并假定构件与包裹的土工合成材料的连续性,而不考虑不同材料的交界面的影响(本文解决了在数学模型中使用界面单元的这一现象)。 Lee等人采用模型试验的方法调查研究被土工材料包裹的碎石桩破坏机制和单个土工格栅的负荷能力。Alexiew等人(2005)描述了用土木布包裹碎石桩的设计原则、技术方法和程序步骤,并强调了用于约束碎石桩的土工布的拉伸模量的重要性。This paper describes 3D finite elem

19、ent analyses that were carried out to simulatethe behavior of a single geosynthetic-encased stone column (GESC) in soft clay usingthe computer program ABAQUS (Hibbitt et al. 2007). To compare the performance of the GESC with a conventional stone column (CSC), parallel analyses were also performed on

20、 a stone column without encasement. This paper describes the results of a comprehensive study that was performed to better understand the load transfer mechanism of CSCs and GESCs. The possibility of using partially encased columns rather than fully encased columns is investigated, and the results a

21、re compared to those from fully encased columns and CSCs. 本文介绍了使用 ABAQUS软件的计算机程序采用三维有限元分析法进行模拟在软土地基上的单一土工合成材料包裹的碎石桩(GESC)的性能(Hibbitt等人。2007年)。采用比较分析法比较传统碎石桩(CSC)与被土工合成材料包裹的碎石桩(GESC)的性能,这种方法也被用于分析裸露碎石桩基的分析。本文介绍一项全面的研究的结果,以便更好地了解传统碎石桩和被土工合成材料包裹的碎石桩的荷载传导机制。对采用部分被土工合成材料包裹的碎石桩比完全包裹的碎石桩更合适的可能性进行调查,结果比较显示,

22、更加倾向于完全包裹的碎石桩和传统的碎石桩。NUMERICAL ANALYSES数值分析Finite element analyses were performed using the program ABAQUS (Hibbitt et al.2007). As the zone of interest has two planes of symmetry, it was only necessary tonumerically model the behavior of the system over a quarter of the domain. Fig. 1 shows a typic

23、al finite-element mesh used in the analyses. In all of the numerical analyses that were performed, the thickness of the soft soil and the length of the stone column were assumed to be 5 m, which is a reasonable length of installation for GESC systems (FHWA, 2006). It was also assumed that the soil a

24、nd column were underlain by a rigid layer. The lateral extent of the soft soil around the stone columnwas selected such that the effects of the vertical boundary conditions on thecalculated results were minimal. As shown in Fig. 1, when the radius of the stone column is 0.4 m the overall radius of t

25、he cylinder is selected to be 2.0 m. At the bottom boundary of the finite-element mesh, the displacements are set to zero in the z direction. The displacements in the x and y directions are set to zero on the circumferential boundary of the soft soil zone.On the planes of symmetry, normaldisplacemen

26、t is restricted. 有限元分析采用ABAQUS软件的程序(Hibbitt等人。2007年)。一个目的区域含有两个对称面,它只需要研究在在这个区域四分之一范围内的系统反应的数学模型。图一显示了在分析时使用的一个典型的有限元网格。在所有的数值 他们演奏了分析,软土层的厚度和碎石桩的长度被假定为5米,这是土工材料包裹碎石桩系统的一个合理的安装长度土工材料包裹碎石桩系统(美国联邦公路管理局,2006年)。另外还假设了土壤和桩都埋在刚性垫层以下。在选择碎石桩周围的软土地基的侧向延伸范围,这样在垂直边界条件的影响的计算结果可以降到最低。如图一所示,当碎石桩的半径为0.4米时,圆柱整体半径为2

27、.0米。在有限元网格的底部边界上,在z轴方向位移设为零。在软土区圆周边界的x轴和y轴方向上设置为零。在对称面上,一般情况下位移将受到一定限制。The finite-element mesh used in the numerical simulations was developed using 6-node linear triangular prism elements for both the stone column and soft soil. Thestone column is modeled using a linear elastic-perfectly plastic mo

28、del with MohrCoulomb failure criterion. The MohrCoulomb model is defined by five parameters:friction angle (), effective cohesion (c), dilatancy angle (), effective Youngs modulus (E), and Poissons ratio (). The parameters used in the numerical analyses are summarized in Table 1. The Mohr-Coulomb pa

29、rameters used in the numerical analyses are similar to the typical values used by other researchers (e.g. Guetif et al. 2007, Ambily and Gandhi 2007). 在数学模拟中采用的有限元网格法发展为同时可在碎石桩和软土地基中使用的6节点线性三棱柱构件。这种碎石桩使用来源于莫尔-库仑破坏准则的线性理想弹塑性模型。莫尔-库仑模型是指由5个参数:摩擦角(),有效内聚力(c),剪胀角(),有效的杨氏弹性模量(E)和泊松比()。在数值分析中使用的参数总结于表1。莫尔

30、-库仑参数用于数值分析类似于其他国家的研究人员使用的典型值。(例如Guetif等人2007年,Ambily和Gandhi 2007年)FIG. 1. Typical finite-element mesh used in the analyses图一:在分析中使用的典型有限元网格The soft soil was modeled as a modified Cam Clay material. Five material parameters were used in the model, namely the slope of the swelling line (), the slope

31、of the virgin consolidation line (), the void ratio at unit pressure (e), slope of the critical state line (M), and Poissons ratio (). The modified Cam Clay parameters used correspond to those obtained for experimental data on soft Bangkok clay (Balasubramian and Chaudhry 1978). These parameters are

32、 provided in Table 1.典型的有限元网格中,软土被建模为一个可滑动粘土改性材料。在这个模型使用五个材料参数,即斜线斜率(),原始坡度巩固线的斜率(),在单位压力下孔隙比(e),临界状态线的坡度(M)和泊松比()。修改后的可滑移粘土参数相当于采用曼谷软粘土进行实验获得的数据(Balasubramian 和 Chaudhry 1978年)。这些参数在表1中列出。The geosynthetic was modeled using 4-node quadrilateral, reduced integration membrane elements. The geosyntheti

33、c was assumed to be an orthotropic linear elastic material, with an assumed Poissons ratio of 0.3. A comprehensive study of numerical results showed that using an isotropic linear elastic material for encasement can increase the bearing capacity of column up to 10% and adversely affect the shape of

34、lateral bulging (Khabbazian et al. 2008). In order not to adversely influence the numerical results, and knowing that the encasement does not carry vertical (compressive) load, the longitudinal elastic modulus of the encasement was decreased to 1% of the circumferential elastic modulus. It should be

35、 mentioned that further decreases in the longitudinal elastic modulus had no effect on the numerical results. 土工合成材料是用模拟的4节点四边形,减少整合的薄膜构件。该土工合成材料被假定为是一个正交的线弹性材料,假设泊松比为0.3。一个综合性研究的数据结果表明,采用各向同性的线弹性材料可以去包裹碎石桩可以提高柱的承载能力高达10,严重影响侧向膨胀的形状(Khabbazian等。2008)。为了不对数据结果产生大的影响,而且已经知道包裹的材料不能承受竖向(压力)荷载,包裹材料的纵向弹性模

36、量减少到径向弹性模量的1%。值得一提的是进一步减小纵向弹性模量,对数值结果的基本没有什么影响。Alexiew (2005) documented that design values of tensile modulus (J) between2000-4000 kN/m were required for the geosynthetic used to encase stone columns ona number of different projects. Consequently, a circumferential elastic modulus of 3000 kN/m was

37、used in the numerical analyses. The circumferential elastic modulus (E) of the geosynthetic was derived from the relationship J = Et, where t is the thickness of geosynthetic, which was assumed to be 5 mm for all of the numerical analyses performed. Alexiew(2005)写到,在不同的项目中,当拉伸模量设计值(J)在2000-4000千牛顿/米

38、之间时,需要用土工合成材料来包裹碎石桩。因此,在数值分析的时候常采用一个切向的弹性模量值3000千牛顿/米。这个土工合成材料的切向弹性模量(E)由公式J=Et得到,其中t是土工合成材料的厚度,这是假设所有的数值为5mm情况下分析完成的。Interface elements, characterized by two sets of parameters, were used to modelinteraction behavior between the geosynthetic and the stone column, and between thegeosynthetic and the

39、 surrounding soft soil. A Mohr-Coulomb failure criterion with zero cohesion was used for the interface elements. The coefficient of sliding friction () between the geosynthetic and the stone column was selected to be 0.5 (=2/3tan) (FHWA, 2006), where is the friction angle of the column material. For

40、 interaction between the geosynthetic and the soft soil, was assumed to be 0.3 (=0.7tan) (Abu-Farsakhl, et al. 2007), where is the friction angle of the soft soil. 界面元素构件含有两个参数,其特点是采用土工合成材料和碎石桩之间,以及土工合成材料和周围的软土地基之间的相互作用的模型。界面元素采用无内聚力的Mohr-Coulomb破坏准则。土工合成材料和碎石桩之间的滑动摩擦系数()取为0.5(=2/3tan)(美国联邦公路管理局,200

41、6年),其中是碎石桩材料摩擦角。对于土工合成材料和软土地基之间的摩擦作用,被假定为0.3(=0.7tan) (Abu-Farsakhl等人,2007年),其中是软土地基的摩擦角。In order to compare the performance of the GESC with a conventional stonecolumn (CSC), parallel analyses were also performed on a stone column withoutencasement. In this case, like interaction between the geosyn

42、thetic and soft soil, the coefficient of sliding friction between the stone column and the soft soil was selected to be 0.3. 为了比较被土工合成材料包裹的碎石桩(GESC)与传统碎石桩(CSC)的性能差异,常在裸露碎石桩上采用平行比较分析。在这种情况下,如土工合成材料和软土地基之间的相互作用,碎石桩和软土地基之间的滑动摩擦系数取0.3。Table 1. Material Parameters 表一:材料参数项目模型(deg) C(kPa)(deg.)E(Mpa) Me碎石

43、桩莫尔-库伦4010600.30.3松软地基改良的滑移粘土0.20.20.21.00 2.00 土工合成材料线弹性6000.30.30.3NUMERICAL RESULTS数值结果In order to determine the stress-displacement behavior on top of the geosyntheticencased stone column, soil nodal points corresponding to the top of the column weresubjected to a series of vertical downward dis

44、placements. During these downward displacements, the average resultant stress on top of the column was recorded , allowing the stress-displacement curve to be drawn accordingly. 为了确定在被土工合成材料包裹的碎石桩顶部的应力与位移之间的关系,土壤结点与碎石桩顶部受到的竖向沉降相一致。在竖向沉降期间,记录碎石桩顶部平均合应力,可以相应的画出应力-位移曲线。Fig. 2 shows the stress-displacem

45、ent response for both a GESC and CSC havingthe parameters listed in Table 1. From Fig. 2, it can be seen that after a very small vertical settlement the mobilized vertical stress on top of the encased column is always greater than the CSC and the difference increases with additional settlement. For

46、example, at a settlement of 25 mm (a common serviceability criteria), the mobilized vertical stress on top of the GESC is 3.8 times greater than that of CSC. This ratio becomes 5.4 for a settlement of 50 mm. 图2分别显示了GESC和CSC应力-位移反应,相应的参数在表1中列出。从图2中,可以看到在一个非常小竖向沉降之后,被合成材料包裹的碎石桩顶部的竖向应力始终大于传统碎石桩,同时增加附加沉

47、降量。例如,当沉降量为25mm(一种常用的适用性标准值)时,被土工合成材料包裹的碎石桩顶部的可变竖向应力比传统碎石桩大了3.8倍。当沉降量为50mm时这个比例变为5.4。 The lateral bulging of the GESC and CSC at a settlement of 50 mm is shown inFig. 3. It is observed that in the CSC, lateral bulging occurs up to depth of 1.2 m(1.5D), after which lateral bulging becomes negligible.

48、 For the GESC, the maximum value of lateral displacement is much less than that for the CSC. However, after a depth of 1D, the GESC experiences more lateral displacement than the CSC. This is attributed to mobilization of more load on top of the GESC (Fig. 2), and the subsequent transmission of greater loads to higher depths in the case of the GESC. This phenomenon is studied further and discussed in more detail in the followingsections. 图3显示了沉降量为50mm时,被土工合成材料包裹的碎石桩和传统碎石桩的横向膨胀量。可以看出,在传统碎石桩中,横向膨胀的最大值发生在1.2米的深度

移动网页_全站_页脚广告1

关于我们      便捷服务       自信AI       AI导航        获赠5币

©2010-2024 宁波自信网络信息技术有限公司  版权所有

客服电话:4008-655-100  投诉/维权电话:4009-655-100

gongan.png浙公网安备33021202000488号   

icp.png浙ICP备2021020529号-1  |  浙B2-20240490  

关注我们 :gzh.png    weibo.png    LOFTER.png 

客服