中圖分類號(hào):TQ323.8 文獻(xiàn)標(biāo)志碼:A 文章編號(hào):1001-5922(2025)07-0013-04
Abstract:Combined with arailway reconstructionand expansion project,the method of laying composite geotextiles on top and botom ofthe polyurethane gravel layer was usedto preventand control the disease of slurryand mud in theroadbed.Taking the composite geotextile structure of polyurethane gravel layer asthe research object,the finite element software was used to establish thecalculation model,and itsmechanical behavior and waterproof performance were studied by numerical simulation.The results showed that the polyurethane gravel layer had good mechanical behavior,which could reduce the displacement,strain and stress of the roadbed.The polyurethane gravel layer had goodanti-seepage performance,which could effectively prevent the wateratthe bottom of the roadbed from pouring into theroadbed along the foundationbed to form slurry;Laying compositegeotextileson top and bottom of the polyurethane gravel layer could playa role inreducing the displacement of the roadbed,homogenizing stress,and strengthening the waterproof performance of the structure.Based on the principle of orthogonal test,the optimal design scheme of polyurethane gravel layer and composite geotextile structure was determined.
Key words:railway subgrade ; slury and mud pumping;; polyurethane gravel layer;composite geotextile; numericalsimulation;orth-ogonal test
針對(duì)有砟軌道路基基床翻漿冒泥的病害,傳統(tǒng)的整治手段有更換基床填土,修建防排水系統(tǒng),設(shè)置封閉層,但是上述方法開挖規(guī)模大,對(duì)軌道結(jié)構(gòu)擾動(dòng)較大[1]。利用天窗點(diǎn)維修施工的運(yùn)營鐵路,開挖道砟、鋪設(shè)土工布是整治翻漿冒泥病害的手段之一,但土工布在長(zhǎng)期作用下易被裹挾、翻卷,且對(duì)基床的強(qiáng)度、剛度無改善作用[2]。國外研究采用瀝青碎石混合料作為結(jié)構(gòu)層,日本、意大利和西班牙等高速鐵路在底座板與基床頂面之間增設(shè) 12~14cm 厚度的瀝青碎石混合料,具有良好的效果[3],但防水性尚待研究。我國膠粘劑行業(yè)發(fā)展迅速,其中聚氨酯與瀝青材料性質(zhì)類似,但其具有良好的機(jī)械性、耐低溫、耐酸堿和與基材良好粘合性的特點(diǎn)[4]。國內(nèi)謝康等提出聚氨酯與碎石結(jié)合作基床表層防水聯(lián)結(jié)層,經(jīng)試驗(yàn)得出聚氨酯碎石層有良好的力學(xué)行為和防水效果[5]。肖宏等以離散元軟件分析聚氨酯發(fā)泡道床模型,表明其具有良好彈性,可減少道砟顆粒的擠壓、摩擦作用,延長(zhǎng)其使用壽命[6]。李鵬飛等依托實(shí)際工程,研究了聚氨酯碎石層整治翻槳冒泥的施工工藝和質(zhì)量控制措施[7]
本文以某鐵路工程為依托,采用Abaqus軟件,建立有限元模型,對(duì)有砟軌道下聚氨酯碎石層上下加鋪復(fù)合土工布結(jié)構(gòu)的力學(xué)性能和防水性能進(jìn)行研究。基于正交試驗(yàn)原理分析了聚氨酯碎石層加鋪復(fù)合土工布結(jié)構(gòu)的優(yōu)化方案,為實(shí)際工程中治理翻漿冒泥提供參考。……