本文選題：高水壓 + 襯砌　； 參考：《重慶交通大學》2015年碩士論文

【摘要】：很多隧道在投入運營以后會出現(xiàn)不同程度的損傷,如混凝土劣化、鋼筋銹蝕、滲漏水嚴重等現(xiàn)象,影響隧道的正常使用。高水壓地段隧道襯砌要承受圍巖壓力以及外水壓力,由于混凝土的滲透性,地下水會在混凝土內(nèi)的裂紋和孔隙內(nèi)滲流給混凝土帶來內(nèi)部孔隙水壓力。此外,隧道內(nèi)部環(huán)境復(fù)雜且地下水中侵蝕性離子較多,會對襯砌混凝土造成腐蝕。隧道襯砌混凝土的碳化和鋼筋銹蝕以及裂損可以降低混凝土的強度,增大混凝土的孔隙度,在水壓作用下促進水體的滲透,與此同時混凝土的滲流場與應(yīng)力場相互作用,影響其損傷的發(fā)展。本文分析了隧道的復(fù)雜環(huán)境對襯砌混凝土耐久性損傷的影響;運用斷裂力學應(yīng)力強度因子分析襯砌在拉壓應(yīng)力作用下裂紋深度對其損傷發(fā)展造成的影響;研究了水壓滲透作用下襯砌混凝土內(nèi)部滲流場與應(yīng)力場之間的耦合關(guān)系,并利用有限元軟件ABAQUS分析滲流—應(yīng)力耦合作用下對混凝土損傷的影響。本文的主要工作及成果如下:①公路隧道通車量的較多,導致隧道內(nèi)部堆積的酸性氣體增多,加快了襯砌混凝土的碳化損傷,降低混凝土的工作性能。富水區(qū)隧道地下水中含有很多侵蝕性離子對混凝土以及鋼筋混凝土中的鋼筋進行侵蝕,使混凝土與鋼筋的有效承載面積減少,損傷量增加。據(jù)此建立了混凝土碳化損傷模型以及鋼筋銹蝕損傷模型。②運用斷裂力學原理,根據(jù)應(yīng)力強度因子針對裂紋深度對襯砌結(jié)構(gòu)損傷影響進行分析。應(yīng)力強度因子是判斷襯砌結(jié)構(gòu)破壞失穩(wěn)的重要因子,其值與襯砌在拉伸、彎矩作用下的軸力和彎矩成正比。當在裂紋發(fā)展初期,其深度對混凝土損傷的影響是很緩慢的,但是到了一定程度后,應(yīng)力強度因子發(fā)生突變,這時裂紋深度很小的擴展都會加劇襯砌混凝土損傷,直至發(fā)生貫穿裂縫影響襯砌的承載能力。③混凝土自身帶有微裂紋、微孔隙等初始損傷,在外界環(huán)境和周圍壓力的作用下,初始損傷逐漸擴展,在高水壓的作用下提高了其滲透性能。隧道襯砌混凝土內(nèi)滲流場與應(yīng)力場相互作用,相互演化,影響著損傷的發(fā)展。本文建立了襯砌混凝土在高水壓下滲流場與應(yīng)力場的耦合關(guān)系,并建立滲流系數(shù)與應(yīng)力、損傷之間的關(guān)系。通過ABAQUS有限元軟件對高水壓下隧道襯砌混凝土進行模擬,得到襯砌混凝土在滲流與應(yīng)力耦合作用下?lián)p傷出現(xiàn)在拱腰部位,并且隧洞內(nèi)側(cè)襯砌損傷最先發(fā)展,損傷與等效塑性應(yīng)變以及滲流系數(shù)具有一定的相關(guān)性。本文的研究可以作為在隧道某個位置和時間設(shè)置各項裝置對損傷進行檢測,及時采取有效措施防止襯砌的損傷提供依據(jù)。
[Abstract]:Many tunnels will be damaged in varying degrees after they are put into operation, such as deterioration of concrete, corrosion of steel bars, serious leakage of water and so on, which will affect the normal use of tunnels.The tunnel lining in high water pressure area must bear the surrounding rock pressure and the external water pressure. Because of the permeability of the concrete, the underground water will bring the internal pore water pressure to the concrete because of the crack in the concrete and the seepage in the pore.In addition, the inner environment of tunnel is complex and there are more erosive ions in groundwater, which will cause corrosion to lining concrete.The carbonization of tunnel lining concrete, the corrosion of steel bar and the cracking can reduce the strength of concrete, increase the porosity of concrete, promote the permeation of water body under the action of water pressure, at the same time, the seepage field and stress field of concrete interact with each other.Affect the development of its damage.In this paper, the influence of the complex environment of tunnel on the durability damage of lining concrete is analyzed, and the influence of crack depth on the damage development of lining under tension and compression stress is analyzed by using the stress intensity factor of fracture mechanics.The coupling relationship between seepage field and stress field in lining concrete under hydraulic seepage is studied, and the effect of seepage and stress coupling on concrete damage is analyzed by finite element software ABAQUS.The main work and results of this paper are as follows: the traffic volume of the 1% 1 highway tunnel increases the accumulation of acid gas in the tunnel, accelerates the carbonation damage of the lining concrete, and reduces the working performance of the concrete.There are a lot of erosive ions in the groundwater of the water-rich tunnel to erode the concrete and the reinforcement in the reinforced concrete, so that the effective bearing area of concrete and steel bar is reduced, and the damage amount is increased.Based on this, the concrete carbonization damage model and steel bar corrosion damage model .2 are established. According to the stress intensity factor, the influence of crack depth on the damage of lining structure is analyzed according to the principle of fracture mechanics.The stress intensity factor is an important factor in judging the failure and instability of lining structure, and its value is proportional to the axial force and moment of lining under the action of tension and bending moment.In the early stage of crack development, the effect of crack depth on concrete damage is very slow, but after a certain extent, the stress intensity factor changes, and the crack depth will increase the damage of lining concrete if the crack depth is very small.Until the load-carrying capacity of concrete affected by the cracks through the lining itself has microcracks, micro-pores and other initial damage, under the external environment and ambient pressure, the initial damage gradually spread,The permeability was improved under the action of high water pressure.The interaction and evolution of seepage field and stress field in tunnel lining concrete affect the development of damage.In this paper, the coupling relationship between seepage field and stress field of lining concrete under high water pressure is established, and the relationship between seepage coefficient and stress and damage is established.Through the simulation of tunnel lining concrete under high water pressure by ABAQUS finite element software, it is concluded that the damage of lining concrete under the coupling of seepage and stress appears at the arch waist, and the lining damage on the inside of the tunnel develops first.There is a certain correlation between damage and equivalent plastic strain and seepage coefficient.The research in this paper can be used as a basis for the installation of various devices at a certain location and time of the tunnel to detect the damage and take effective measures to prevent the damage of the lining in time.
【學位授予單位】：重慶交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U451.4;U455.91

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本文編號：1734808