铁道标准设计
鐵道標準設計
철도표준설계
Railway Standard Design
2015年
11期
26-30,31
,共6页
青藏铁路%多年冻土%路堑边坡%病害特征%防护措施
青藏鐵路%多年凍土%路塹邊坡%病害特徵%防護措施
청장철로%다년동토%로참변파%병해특정%방호조시
Qinghai-Tibet Railway%permafrost%cutting slope%disease characteristic%protective measure
青藏铁路格拉段多年冻土区共有路堑边坡78处,长约15.6 km,其稳定性直接关系到线路安全运营。根据现场调查,分析其稳定性状况、病害形式、影响因素及机理,讨论防治措施的合理性。结果表明：先后有15处出现病害,其中4处失稳,病害问题值得重视；病害形式包括坡面冲刷、纵向裂缝、防护结构破坏、滑塌、坡脚鼓胀等；病害位置以边坡上侧为主,而非阳坡侧,堑顶是最薄弱的部位,发育过程表现为周期性和波动性的恶化；地表水和冻结层上水的热侵蚀及活动层冻融作用是病害的主要原因,病害机理包括地表水冲刷、滞水冻胀和冻融循环；经过运营期检验,无防护的坡面容易冲刷变形,封闭式锚喷混凝土面容易滞水冻胀破裂,轻型、柔性的骨架护坡和L型挡墙防护效果较好。
青藏鐵路格拉段多年凍土區共有路塹邊坡78處,長約15.6 km,其穩定性直接關繫到線路安全運營。根據現場調查,分析其穩定性狀況、病害形式、影響因素及機理,討論防治措施的閤理性。結果錶明：先後有15處齣現病害,其中4處失穩,病害問題值得重視；病害形式包括坡麵遲刷、縱嚮裂縫、防護結構破壞、滑塌、坡腳鼓脹等；病害位置以邊坡上側為主,而非暘坡側,塹頂是最薄弱的部位,髮育過程錶現為週期性和波動性的噁化；地錶水和凍結層上水的熱侵蝕及活動層凍融作用是病害的主要原因,病害機理包括地錶水遲刷、滯水凍脹和凍融循環；經過運營期檢驗,無防護的坡麵容易遲刷變形,封閉式錨噴混凝土麵容易滯水凍脹破裂,輕型、柔性的骨架護坡和L型擋牆防護效果較好。
청장철로격랍단다년동토구공유로참변파78처,장약15.6 km,기은정성직접관계도선로안전운영。근거현장조사,분석기은정성상황、병해형식、영향인소급궤리,토론방치조시적합이성。결과표명：선후유15처출현병해,기중4처실은,병해문제치득중시；병해형식포괄파면충쇄、종향렬봉、방호결구파배、활탑、파각고창등；병해위치이변파상측위주,이비양파측,참정시최박약적부위,발육과정표현위주기성화파동성적악화；지표수화동결층상수적열침식급활동층동융작용시병해적주요원인,병해궤리포괄지표수충쇄、체수동창화동융순배；경과운영기검험,무방호적파면용역충쇄변형,봉폐식묘분혼응토면용역체수동창파렬,경형、유성적골가호파화L형당장방호효과교호。
There are 78 cutting slopes in permafrost regions along Qinghai-Tibet Railway, with the length of about 15. 6 km, and the stability of the slopes is directly related to the safe operation of the line. This paper analyzes stability conditions, forms of defects, influencing factors and mechanisms of the slopes based on field surveys. The rationality of the protective measures is also discussed. The results show that the number of defected cutting slopes comes to 15, 4 of which lost their stability. The defects are characterized by surface scouring, longitudinal cracks, destruction of protective structures, collapse and toe swollen. The defects are mainly located at the upper part of slopes, rather than the sunny side, and the top of the cutting is the weakest part. The development is characteristics of periodic process and fluctuated deterioration. Thermal erosion of external water and suprapermafrost water, freeze-thaw action of active layer are the main causes of the defects. Defect mechanisms include erosion of external water, frozen expansion of stagnant water and freeze-thaw circulation. The inspection in the operation period shows that slopes without protection are prone to scouring and deformation, closed anchor-spray concretes are likely to be ruptured by freezing expansion force of stagnant water, light and flexible frame structure and L-type retaining wall are effective in protection.
