文章摘要
江浩源,王正中,王羿,刘铨鸿,葛建锐.大型弧底梯形渠道“适缝”防冻胀机理及应用研究[J].水利学报,2019,50(8):947-959
大型弧底梯形渠道“适缝”防冻胀机理及应用研究
Study on anti-frost heave mechanism and application of “reasonable joints” for large-size trapezoidal canal with arc-bottom
投稿时间:2019-04-29  
DOI:10.13243/j.cnki.slxb.20190299
中文关键词: 渠道冻胀破坏  冻土水-热-力耦合  “适缝”防冻胀  应力分布均匀度  布设形式
英文关键词: frost heave damage of canal  thermo-hydro-mechanics coupling of frozen soil  anti-frost heave with “reasonable joints”  uniformity of distribution of stress  layouts
基金项目:国家重点研发计划项目(2017YFC0405102);国家自然科学基金项目(51279168);冻土工程国家重点实验室开放基金项目(SKLFSE201801)
作者单位E-mail
江浩源 西北农林科技大学 旱区寒区水工程安全研究中心 旱区农业水土工程教育部重点实验室, 陕西 杨凌 712100  
王正中 西北农林科技大学 旱区寒区水工程安全研究中心 旱区农业水土工程教育部重点实验室, 陕西 杨凌 712100
中国科学院 寒区旱区环境与工程研究所冻土工程国家重点实验室, 甘肃 兰州 730000 
wangzz0910@163.com 
王羿 西北农林科技大学 旱区寒区水工程安全研究中心 旱区农业水土工程教育部重点实验室, 陕西 杨凌 712100  
刘铨鸿 西北农林科技大学 旱区寒区水工程安全研究中心 旱区农业水土工程教育部重点实验室, 陕西 杨凌 712100  
葛建锐 西北农林科技大学 旱区寒区水工程安全研究中心 旱区农业水土工程教育部重点实验室, 陕西 杨凌 712100  
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中文摘要:
      旱寒区渠道工程上预先在衬砌板易产生裂缝处顺其自然设置纵缝,以防止冻胀破坏。为探明这种纵缝设置的防冻胀机理及其最佳布设形式,基于冻土水-热-力三场耦合理论,考虑纵缝填充的接触本构及衬砌-冻土相互作用,建立了旱寒区常用的大型窄深式弧底梯形渠道冻胀仿真分析模型,以衬砌板上下表面沿周长正应力分布均匀度为一级指标,以其截面正应力满足强度要求为二级指标,对纵缝设置位置、宽度、个数及其组合削减渠道冻胀效果进行了研究。结果表明:弧底衬砌板属于薄拱结构,渠坡板为梁结构,纵缝为可移动弹性铰;纵缝位置及宽度的变化不断调整拱-梁结构的刚度及弹性铰的约束刚度,以适应基土冻胀变形,使衬砌板表面应力均匀化,从而削减冻胀;但纵缝过宽会过度削弱弧底拱效应,使弧底中心和坡板上表面及坡脚下表面拉应力过大,易导致冻胀破坏;单独设缝时坡脚位置设缝防冻胀效果最好,而组合设缝削减冻胀效果更优,尤其是坡脚与坡板组合设缝。以新疆某供水渠道为例,采用坡脚与坡板1/4、3/4处组合设缝,缝宽取1 cm,可满足两级指标,削减冻胀效果最优,可为旱寒区大型渠道防冻胀合理布设纵缝(适缝)提供科学依据。
英文摘要:
      The longitudinal joint is set in the crack-generation area in advance to reduce frost heave of lin-ing canal in arid-cold region. In order to explore the anti-frost heave mechanism and optimal layouts of lon-gitudinal joints for large-size narrow-deep trapezoidal canal with arc-bottom,a frost heave model was devel-oped based on the thermo-hydro-mechanics theory, considering contact constitutive model of longitudinal joint and soil-lining interaction. Taking the uniformity of distribution of normal stress along the circumferen-tial length on the upper and lower surfaces of lining slab as the first-order index and the normal stress of its cross section satisfying the strength requirement as the second-order index, the effect of reduction of frost heave was studied for position, width and combination of longitudinal joint. The results show that lin-ing slab of arc-bottom belongs to thin-arch structure, slope slab is beam structure, and longitudinal joint is a movable elastic hinge. The change of position and width of joint constantly adjusts the stiffness of arch-beam structure and the constraint stiffness of elastic hinge, which can adapt to the frost heave deforma-tion and homogenize the surface stress of lining so as to reduce the frost heave. But the arch effect of arc-bottom would be weakened excessively with the wider longitudinal joint, which results in excessive ten-sile stress in the upper surface of center of arc-bottom and slope slab and the lower surface of slope toe, leading to frost heave failure. The effect of anti-frost heave is the best with the joint at the slope toe, while the combination-joints is better especially at the slope slab and slope toe. Combined with a wa-ter-supply canal in Xinjiang, the combination-joints is designed at the slope toe and the 1/4 and 3/4 slope slab with the 1cm-joint, which can meet the above indexes. The results can provide scientific basis for rational layout of longitudinal joints in large-size canals in arid-cold region.
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