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哪位大哥帮忙翻译下感激啊! [复制链接]

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离线ccl8973
 
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只看楼主 倒序阅读 使用道具 楼主  发表于: 2007-03-29
— 本帖被 sunjun 执行加亮操作(2007-04-05) —
    The characteristics of vacuum consolidation and the advantages of preloading soft clayey deposits by combining vacuum pressure treatment with embankment loading are discussed . Laboratory oedometer test results show that vacuum pressure induces less or about the same settlement compared to an applied surcharge load of the same magnitude. If the applied vacuum pressure is larger than the lateral stress required to maintain a K。condition (no horizontal strain), there will be inward lateral displacement and the vacuum pressure will induce less sttlement.  In cases where the bottom of the soft clayey deposit is deposit is drained (e.g. where the clay overlies a sand or gravel layer),application of a vacuum pressure will cause less consolidation than an equivalent surcharge load because than at the bottom drainage boundary effectively the vacuum pressure can not be applied. For this type of subsoil condition it is suggested than if vacuum consolidation is combined with the use of perfabricated vertical drains (PVDs) for ground improvement, the PVDs should not penetrate the entire clayey layer. An equation for calculating the optimum penetration depth has been derived for this case. The advantages of combining vacuum pressure with embankment loading are discussed in terms of increasing the effective surcharge loading,reducing construction time in the case of road construction,and reducing the preloading-induced lateral displacement of the subsoil.
    For many engineering constructions on soft some form on ground improvement is often required. Preloading is a common method used to provide ground improvement. The surcharge pressure required for preloading can be either due to the weight of imposed fill material (e.g.embankment) and/or the application of a vacuum pressure to the pore fluid contained within the soil. Consolidating soft clayey deposits by applying a vacuum pressure has several advantages over embankment loading e.g. no fill material is requied,construction periods are generally shorter and there is no need for heavy machinery. In addition,the vacuum perssure method does not put any chemical admixtures into the ground and consequently it is an environmentally friendly ground improvement method. However, vacuum consolidation also has shortcmings,e.g the applied vacuum is limited by atmospheric pressure and it may cause cracks in the surrounding surface area due to consolidation-induced inward lateral displacement of the ground. Therefore, in some cases, the combination of vacuum pressure and embankment loading may provide overall ground improvement.
    In this paper, the characteristics of vacuum consolidation are first discussed and illustrated with some laboratory test data, and the advantages of combining vacuum pressure with embankment loading are explained in general terms.
Characteristics of Vacuum Consolidation
    Magnitude of vacuum pressure induced settlement. Laboratory oedometer tests under surcharge load and vacuum pressure were conducted and compared to Maruto Multiple Oedometer Apparatus with a sample size of 60 mm in diameter and typicall 20 mm in height. Soil samples used were reconstituted Ariake clay (Ariake clay) and Ariake clay and sand mixture (mixed soil).some of the physical and mechanical properties of the samples are lested in Table 1.
Table 1. Some physical and mechanical properties of the soil samples

\
    Under one-way drainage condition and using Ariake clay samples, the comparisons of the  settlement versus time curves are given in Figs 1(a) and (b) for 0 and 80 kPa initial effective vertical stress in the samples, respectively (after Chai et al.2005). It can be seen that when the initial vertical effective stress is 0, the vacuum pressure-induced settlement is less than observed under the corresponding surcharge load (Fig.1(a)). For the case where the initial vertical effective stress ia 80 kPa, the setttlements induced by vacuum pressure and surcharge load are almost the same (Fig.1(b)). Generally,where the vacuum pressure can result the same settlement as a corresponding surcharge load under oedometer conditions depends on whether a K。condition (no horizontal strain) can be maintained Under oedometer conditions and with an incermental vacuum pressure loading,if there is any lateral displacement in the sample, there will eventually be no confining stress applied by the oedometer constraining ring, and the only horizontal stress will be due to the vacuum pressure, Therefore, if the vacuum pressure is larger than the stress required to maintain a K。condition, there will be inward lateral displacement and the vacuum pressure will induce less settlement than the surcharge load. Otherwise there will be no lateral deformation and the vacuum pressure will induce the same settlement as an equivalent load. The condition for inward lateral displacement to occur can be given as follows:


Where K。is the at-rest horizntal earth pressure coefficient,  is initial (in situ) vertical effective stress, and  is the incremental vacuum pressure.
离线happywavelet

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只看该作者 1楼 发表于: 2007-04-03
我可以在下周一前给您翻译出来,希望您不是太急。
离线happywavelet

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只看该作者 2楼 发表于: 2007-04-04
前两段:
本文讨论了真空固结的特点、结合真空加压和堆载加荷的软弱粘土状沉积物的预加压优点。室内固结测试结果表明:同施加相同数量及的超载相比,真空加压引起相似的沉降。如果为了维持K.0条件而施加大于横向应力的真空压力(非水平应变),则将引起向内的横向位移,同时真空压力一起的沉降较小。在一些案例中,软粘土状沉积物底部是可排水的(比如粘土位于沙或者砾石层上),由于在底部排水边界上真空压力不能有效施加,此时施加真空压力引起的固结将小于等价的超载时情况。对于这种地基,如果结合使用预制竖向排水管(PVDs)来通过真空固结进行土体改良,则建议PVDs不穿透整个粘土土层。针对此种情况,提出了一个计算优化的穿透深度的公式。本文讨论了在公路建设中,真空压力法和堆载加荷相结合在增加有效超载、降低工期和减少预加载引发的地基侧向位移等方面的优势。
对于很多位于软弱土层上的工程来说,通常需要进行土体改良,而预加载是一种常用的方法。预加载需要的超载压力可以通过其上堆积物的重量来得到(堆载加荷)和/或者对土体中的空隙水施加真空压力。真空加压在粘土沉积物固结方面具有较多优势,比如无需堆积物、施工期一般更短和无需重型机器。此外,真空加压法不会把任何化学物质混进土体中去,因此它是一种环境友好的土体改良方法。尽管如此,真空固结法也有其不足,比如真空受限于大气压力,并且由它产生的固结可引起向内的侧向位移,进而引起周围表面区域的破裂。因此,在一些工程中,通过真空加压和堆载加压相结合来实现土体改良。
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sunjun 土币 +80 经典回复 2007-04-04
离线sunjun

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只看该作者 3楼 发表于: 2007-04-05
happywavelet真是热心人啊,先替楼主向你道谢!
海纳百川,有容乃大;
壁立千仞,无欲则刚
离线sunjun830109

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只看该作者 4楼 发表于: 2007-04-15
happywavelet真是热心人啊
离线tjdx
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只看该作者 5楼 发表于: 2007-04-16
楼上的id我以为是孙均院士亲自来呢
离线104072005

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只看该作者 6楼 发表于: 2007-04-16
happywavelet真是活雷峰啊.
离线joidon

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只看该作者 7楼 发表于: 2007-04-16
引用第5楼tjdx于2007-04-16 23:01发表的  :
楼上的id我以为是孙均院士亲自来呢


哈哈,孙俊先生也是牛人哦
离线palette
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只看该作者 8楼 发表于: 2007-06-13
特点真空巩固和优势预软粘土存款结合的真空压力处理路堤 装载了讨论. 实验室Oedometer试验结果表明,真空压力诱使或少大约同一结算相比,应用附加 负荷越大. 如果采用真空压力大于侧向应力要保持一个K . (没有横向株) , 会有外来侧移和真空压力会诱使sttlement少. 的情况下,底部的软粘土存款是存款排出(如在粘土之上一 砂或砂砾层) ,应用了真空压力将导致较少固结比相等的附加负荷,因为在比 底部排水边界有效的真空压力不能适用. 对于这样的地基条件,但建议如果不是真空固结结合使用perfabricated 竖井(板) ,为改善地面,排水不应穿透整个粘土层. 方程计算的最佳穿透深度第七二三此案. 优势相结合的真空压力与路基不稳的讨论,在提高效益的附加荷载,减少建筑 时间在公路建设,并减少预诱导横向位移的心土. 许多工程建设软某种形式的地面改善往往需要. 预是一种常见的方法,以提供地面改善. 附加压力所需预可以要么由于重量施加填料( e.g.embankment )和/或 应用真空压力孔隙流体控制在土壤中. 加固软粘土存款用真空压力有几个好处超过路堤加载,例如 无填料是requied ,建设周期普遍缩短,也无须重型机械. 此外,真空高压锅方法,没有提出任何化学外加剂进入地面,因此,它是一种环保 友好地面改进方法. 然而, 真空固结也shortcmings ,文理应用真空有限公司,是由大气压力,而且可能造成裂缝的 周边表面积由于综合性外来侧移的地面. 因此,在某些情况下,结合真空压力和路堤荷载可提供地面整体改善. 本文的特点,真空固结是第一次讨论,并给出了一些实验数据, 与优势相结合的真空压力与路基不稳的解释,在一般条款. 特色真空固结震级真空压力致解决. 实验室测试压缩下附加荷载和真空压力进行了比较多马鲁托Oedometer试验仪器,以 样本规模为60毫米直径typicall 20毫米的高度. 土壤样品用的是重组粘土(粘土) ,粘土和砂混合物(混合土) . 一些身体 和力学性能的样本lested见表1 . 表1 . 一些物理和力学性能的土壤样品\下单向排水条件和使用粘土样品 比较的沉降随时间变化曲线,在图1 ( a )和( b )为0和80军 初始竖向有效应力的样本,分别为(后柴内皮al.2005 ) . 由此可以看到,当初始垂直有效应力为0 , 真空压力诱导沉降小于下观察相应的附加载荷( 2+ (一) ) . 的情况下,初始垂直有效应力监80 kPa时, setttlements的诱导真空压力及附加荷载几乎相同( 2000 ( b )款) . 一般说来,在真空压力可导致同样的方式解决了相应的附加荷载下固结条件取决于 一k . (没有横向株) ,可保持在压缩条件下,以一个incermental真空压力负荷,如果有 任何侧向位移样本,但最终没有围应力适用的压缩制约戒指 而唯一的水平应力会因真空压力,因此 如果真空压力大于强调要保持一个K . 条件 会有外来侧移和真空压力会诱使那么多交的附加荷载. 否则便没有侧向变形和真空压力会诱使同一居民点作为一个等效负载. 条件为外来侧移发生,可以考虑如下: 其中K . 就是在休息horizntal土压力系数,是初始(原位)垂直有效应力, 是渐进的真空压力.
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梦无痕 鲜花 +1 - 2007-06-13
lzx761 鲜花 +1 - 2007-06-13
离线fzwind

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只看该作者 9楼 发表于: 2007-06-20
论坛的热心人真多
离线ssnqt00
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只看该作者 10楼 发表于: 2007-08-09
特点真空巩固和优势预软粘土存款结合的真空压力处理路堤?
哈哈
离线sztkyyhz

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只看该作者 11楼 发表于: 2007-08-23
大家帮助大家,论坛风气真不错。
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