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极地高密度烧结雪层无侧限压缩离散元分析

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从新雪变成老雪的过程叫作"烧结",对雪层进行人工压实和烧结是建设极地机场跑道的主要方法,雪层烧结使雪颗粒间胶结尺寸增加,雪层强度增强。为探究人工压实烧结雪层在无侧限压缩荷载下的胶结接触破坏规律和承力机理,本研究采用三维离散元方法模拟了密实烧结雪层无侧限压缩试验,在室内试验结果基础上构建雪的胶结接触模型并标定接触参数,通过建立压实烧结雪离散元模型,进行了无侧限压缩加载模拟。模拟的结果验证了离散元模拟的有效性并表明:(1)在无侧限压缩下,密实烧结雪试样在剪切带区域发生集中胶结破坏,胶结断裂主要归因于接触在受拉状态下受剪;(2)冰雪颗粒的破碎会影响冰雪道面的抗剪强度,因此需要慎重考虑高应力对内摩擦角的影响。本研究将为极地地区通过压实烧结雪层简单现场试验预测其复杂应力路径下的力学特征提供科学支持。
Discrete element method analyses of the polar high-density sintered snow under the unconfined compression tests
Artificial snow compaction and sintering,which is the process of turning fresh snow into general snow,is a basic method for the construction of polar snow runway.Snow compaction densifies the snow pavement and snow sintering increases the bond size between snow particles and hence improves the strength of the snow pavement.In order to investigate the mechanism of the bond breakage evolution and stress bearing mechanism of the dense sintered snow under the unconfined compression test(UC),the three-dimensional discrete element method(DEM)was employed.A bond contact model for the sintered snow was introduced and the contact parameters were calibrated through published experiments results,firstly.Then,the discrete element model was established and the UCs were carried out;The DEM results are verified and the conclu-sions are as follows:(1)Intensive bond breakage occurs at the shear band of the dense sintered snow sample under UC,with bond fracture predominantly attributed to shearing under tension.(2)The crushing of snow particles affects the shear strength of the snow pavement,and the effect of high stress on the internal friction angle needs to be carefully considered.The study provides scientific support to predict the mechanical cha-racteristics of compacted sintered snow under complex stress paths through simple in-situ tests in polar re-gions.

polar regioncompacted snowsnow sinteringdiscrete element methodunconfined compres-sion test

李涛、霍海峰、胡彪、贾汶韬、陈庆炜

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中国民航大学交通科学与工程学院,天津 300300

交通部机场工程安全与长期性能科研基地,天津 300300

极地 压实雪 雪烧结 离散元 无侧限压缩试验

国家自然科学基金中央高校基金天津市交通运输委员会面上项目

5180919331220200402019-18

2024

极地研究
国家海洋局极地考察办公室 中国极地研究中心

极地研究

CSTPCD北大核心
影响因子:0.638
ISSN:1007-7073
年,卷(期):2024.36(2)
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