【正文】 ome settlement such as road embankments, storage tanks, lowrise buildings, lightly loaded foundations, etc. This form of ground improvement is also monly 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 potential of sands. 碎石樁已經(jīng)被越來越多的用于地基的改善工程，特別是能承受一些沉降的結(jié)構(gòu)，例如，公路路堤、存儲倉庫、低層建筑以及受到較輕荷載的基礎(chǔ)等。 碎石 柱 的 廣泛使用，是因為 它 成功 地 證明 了自身 在提高承載能力，降低整體 沉降 和 不均勻 沉降， 增加 沉降 的 時間 速率 ，減少砂 土地基 液化 可能性方面的能力 。1975年），一般 的 剪切破壞（ Madhav和 Vitkar 1978年）， 滑移破壞（ Aboshi 等人 1979） 。 In very soft soils, due to the lack of required lateral confining pressure, the use of stone 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 highstrength 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. (2020) conducted tests to 附件 C：譯文 C3 investigate the effect of geogrid reinforcement on bulging and loadcarrying capacity of a single stone column in soft clay. Murugesan and Rajagopal (2020, 2020) performed model tests and numerical analyses to study the behavior of a single geosyntheticencased stone column with a limited zone of soil influence (a tributary approach to column group behavior). In the numerical analyses, Murugesan and Rajagopal (2020) performed axisymmetric analyses and assumed continuum elements for the geosynthetic without considering the behavior of the interface between different materials (this paper addresses this phenomenon by using interface elements in the numerical model). Lee et al. Lee et al. (2020) investigated the failure mechanism and load carrying capacity of individual geogrid encased stone columns by model tests. Alexiew et al. (2020) described the design principles, technologies, and procedures for geotextile encased stone columns and emphasized the importance of the tensile modulus of the geotextile that is used for column confinement. 在非常 松 軟 的軟土地基上 ，由于所需的側(cè)向圍壓不足， 碎石樁的使用 可能會出現(xiàn) 問題。 使用 一種 高強(qiáng)度土工合成材料，不但 可以 增加了 碎石樁的強(qiáng)度 ，而且還可以防止 碎石樁向著 周圍 松軟地基發(fā)生側(cè)向位移 。 Murugesan和 Rajagopal（ 2020年， 2020年） 進(jìn)行模型試驗和數(shù)值分析，以研究 在一個限定區(qū)域內(nèi)的單個被 土工合成 材料 包裹的碎石樁的性能影響 （ 研究群樁效應(yīng)的其他途徑 ）。 Lee等人采用模型試驗的方法調(diào)查研究被土工材料包裹的碎石樁破壞機(jī)制和單個土工格柵的負(fù)荷能力。 This paper describes 3D finite element analyses that were carried out to simulate the behavior of a single geosyntheticencased stone column (GESC) in soft clay using the puter program ABAQUS (Hibbitt et al. 2020). To pare the performance of the GESC with a conventional stone column (CSC), parallel analyses were also performed on a stone column without encasement. This paper describes the results of a prehensive 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 are pared to those from fully encased columns and CSCs. 本文介紹了使用 ABAQUS軟件的計算機(jī)程序 采用 三維有限元 分析法 進(jìn)行模擬在軟土地基上的 單一土工合成材料包裹的 碎石樁 （ GESC） 的性能 （ Hibbitt等人。 采用比較分析法比較傳統(tǒng)碎石樁（ CSC）與被土工合成材料包裹的碎石樁（ GESC）的性能，這種方法也被用于分析裸露碎石樁基的分析。 對采用部分被土工合成材料包裹的碎石樁比完全包裹的碎石樁更合適的可能性進(jìn)行調(diào)查，結(jié)果比較顯示，更加傾向于完全包裹的碎石樁和傳統(tǒng)的 附件 C：譯文 C4 碎石樁。 2020年）。圖一顯示了在分析 時 使用 的 一個典型的有限元網(wǎng)格。 另外 還假設(shè)了土壤和 樁都埋在 剛性 墊 層 以下 。如圖一 所示 ， 當(dāng) 碎石樁的 半徑為 時， 圓 柱 整體半徑為 。在軟土區(qū)圓周邊界 的 x軸 和 y軸 方向上設(shè)置為零。 The finiteelement mesh used in the numerical simulations was developed using 6node linear triangular prism elements for both the stone column and soft soil. The stone column is modeled using a linear elasticperfectly plastic model with Mohr– Coulomb failure criterion. The Mohr–Coulomb model is defined by five parameters: ψ), effective Young’s modulus (E), and Poisson’s ratio (ν). The parameters used in the numerical analyses are summarized in Table 1. The MohrCoulomb parameters used in the numerical analyses are similar to the typical values used by other researchers (. Guetif et al. 2020, Ambily and Gandhi 2020). 在數(shù)學(xué)模擬中采用的有限元網(wǎng)格法發(fā)展為同時可在碎石樁和軟土地基中使用的 6節(jié)點(diǎn)線性三棱柱構(gòu)件。莫爾 庫侖模型是指由 5個參數(shù) ： 摩擦角（ φ ），有效 內(nèi) 聚力（ c39。在數(shù)值分析中使用的參數(shù) 總結(jié)于表 1。（ 例 如 Guetif等人 2020年， Ambily和 Gandhi 2020年） FIG. 1. Typical finiteelement mesh used in the analyses 圖一：在分析中使用的典型有限元網(wǎng)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 (κ), the slope of the virgin consolidation line (λ), the void ratio at unit pressure (e), slope of the critical state line (M), and Poisson’s ratio (ν). The modified Cam Clay parameters used correspond to those obtained for experimental data on soft Bangkok clay (Balasubramian and Chaudhry 1978). These parameters are provided in Table 1. 典型的有限元網(wǎng)格中 ， 軟土被建模為一個 可滑動 粘土改性材料。修改后的 可滑移粘土參數(shù) 相當(dāng)于采用曼谷軟粘土進(jìn)行 實驗獲得的 數(shù)據(jù) （ Balasubramian 和 Chaudhry 1978年）。 The geosynthetic was modeled using 4node quadrilateral, reduced integration membrane elements. The geosynthetic was assumed to be an orthotropic linear elastic material, with an assumed Poisson’s ratio of . A prehensive 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 lateral bulging (Khabbazian et al. 2020). In order not to adversely influence the numerical results, and knowing that the encasement does not carry vertical (pressive) load, the longitudinal elastic modulus of the encasement was decreased to 1% of the circumferential el