【摘要】：概要介紹龍巖雙永高速公路K227超高路塹邊坡的地形地貌、地質(zhì)條件、變形破壞過程及特征,結(jié)合邊坡穩(wěn)定度反分析思路、強度折減法和開挖有限元仿真技術(shù)對該邊坡變形孕育過程進(jìn)行模擬分析和定量評估。采用一種基于應(yīng)力張量差值的增減變化及其變化量的正負(fù)分區(qū)來確定邊坡開挖松弛區(qū)的數(shù)值方法,解釋路塹高邊坡開挖卸荷松弛的力學(xué)機理;模擬重現(xiàn)了挖方邊坡經(jīng)歷穩(wěn)定性緩慢上升的卸荷回彈階段、穩(wěn)定性線性下降的剪切破裂階段和穩(wěn)定性急劇下降的失穩(wěn)破壞階段的全過程中應(yīng)力調(diào)整、塑性屈服、滑面孕育和變形破壞的演化規(guī)律和發(fā)展趨勢,揭示了邊坡由于快速工程開挖擾動,使?jié)撛谲浫鯉С浞直┞?并切斷坡腳力學(xué)支撐,伴隨巖土卸荷松弛及強度弱化,產(chǎn)生坡頂巖土張裂變形、深層軟弱帶剪切蠕動和坡腳沿結(jié)構(gòu)面臨空剪出的失穩(wěn)機制;間歇性降雨入滲的巖土增重及附加水壓使滑坡表現(xiàn)出時滑時停的特征;邊坡整體處于臨界狀態(tài),在繼續(xù)開挖或持續(xù)暴雨沖擊條件下,可能導(dǎo)致穩(wěn)定性驟降,從滑動階段轉(zhuǎn)化為劇滑階段。最后,對應(yīng)急搶險對策、治理方案規(guī)劃及線路調(diào)整設(shè)想等問題進(jìn)行討論與反思,為邊坡病害治理提供了理論依據(jù)。
[Abstract]:This paper briefly introduces the topography and geomorphology, geological conditions, deformation and failure process and characteristics of K227 ultra-high cutting slope of Longyan Shuangyong Expressway. Combined with the idea of back analysis of slope stability, strength reduction method and excavation finite element simulation technology, the deformation preparation process of the slope is simulated, analyzed and quantitatively evaluated. A numerical method based on the increase and decrease of stress tensor difference and its variation is used to determine the excavation relaxation zone of slope excavation, and the mechanical mechanism of excavation unloading relaxation of cutting high slope is explained. The evolution law and development trend of stress adjustment, plastic yield, sliding surface gestation and deformation failure of excavated slope are simulated and reproduced in the whole process of unloading springback stage of slow rise of stability, shear fracture stage of linear decline of stability and instability failure stage of sharp decline of stability. It is revealed that the potential weak zone of slope is fully exposed and the mechanical support of slope foot is cut off due to excavation disturbance of rapid engineering. With the relaxation of rock and soil unloading and the weakening of strength, the tension and crack deformation of rock and soil at the top of the slope, the shear peristalsis of the deep weak zone and the instability mechanism of the slope foot facing empty shear along the structure are produced. The rock and soil weight gain and additional water pressure of intermittent rainfall infiltration make the landslide show the characteristics of sliding and stopping, and the slope as a whole is in a critical state, which may lead to a sudden drop in stability under the condition of continuous excavation or continuous rainstorm impact, which may change from sliding stage to sharp sliding stage. Finally, the emergency countermeasures, treatment scheme planning and line adjustment are discussed and reflected, which provides a theoretical basis for the treatment of slope diseases.
【作者單位】： 福州大學(xué)環(huán)境與資源學(xué)院;地質(zhì)工程福建省高校工程研究中心;中國公路工程咨詢集團(tuán)有限公司中咨華科交通建設(shè)技術(shù)有限公司;
【基金】：國家自然科學(xué)基金資助項目(41002127) 交通運輸部建設(shè)科技項目(201331849A130) 福建省交通運輸科技項目(201242)~~
【分類號】：U418.5
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本文編號：2508729