軟巖大變形高速鐵路隧道二次襯砌支護時機研究
發(fā)布時間：2018-07-15 09:27
【摘要】：進入二十一世紀以來,我國經(jīng)濟建設速度明顯提高,獲得了前所未有的發(fā)展。經(jīng)濟發(fā)展帶來對交通運輸?shù)男枨?因此,我國高鐵建設在近些年獲得了長足的發(fā)展。高速鐵路建設需要修建隧道工程的情況很多。在實際工程當中,由于隧道本身施工進度慢、難度大,因此許多隧道工程會成為整條高鐵隧道的控制工程。雖然在地質(zhì)較好的情況下隧道的工期、質(zhì)量以及安全能夠得到很好的保證,但是在某些地質(zhì)條件較差的情況,如遇到高地應力軟巖大變形的情況,就會因為圍巖變形量大導致工期延長、安全性下降和造價提高。 在長期的研究中,將初期支護承受全部荷載二次襯砌作為安全儲備的理念深入人心。初期支護承受全部荷載,指圍巖在初期支護的作用下完全可以實現(xiàn)自穩(wěn)；二次襯砌作為安全儲備,并不是二襯不受力,而是二襯受力與其承載能力相比可以忽略,二襯的主要作用是提高復合襯砌結構的耐久性,抵抗圍巖可能發(fā)生的惡化。 圍巖的自承載能力在當今隧道工程的設計與施工中越來越受到重視,將圍巖與支護視作一個統(tǒng)一體來承受荷載。為了使圍巖的自承能力充分得到實現(xiàn),可以允許圍巖在隧道開挖以及后期中具有一定的變形,充分發(fā)揮圍巖自承能力,這樣同時也會減小圍巖對支護結構的作用,有效地改善圍巖的應力狀態(tài)。為防止圍巖變形過大進入松動狀態(tài),滿足二襯在合理范圍內(nèi)發(fā)揮作用,支護時機就必須合理。支護過早,圍巖應力得不到釋放,施加在二襯上的荷載過大,必須要求二次襯砌具有更高的剛度強度,同時也會存在較大的安全隱患,如支護過晚,圍巖位移受不到限制,會因為圍巖破壞給二襯施加更大壓力,由于位移過大造成。所以選擇合理的支護時機成了隧道工程的重點。
[Abstract]:Since entering 21 century, our country economy construction speed has improved obviously, has obtained the unprecedented development. Economic development brings the demand of transportation. Therefore, the construction of high-speed railway in China has made great progress in recent years. The construction of high-speed railway requires the construction of tunnels. In the actual project, due to the slow construction progress of the tunnel itself, many tunnel projects will become the control project of the whole high-speed railway tunnel. Although the time limit, quality and safety of the tunnel can be guaranteed well under the condition of good geology, in some cases of poor geological conditions, such as large deformation of soft rock with high ground stress, Because of the large deformation of surrounding rock, the construction period is prolonged, the safety is decreased and the cost is increased. In the long-term research, the idea that the initial support bears all the load and the secondary lining as the safety reserve is deeply accepted. The initial support bears all the loads, which means that the surrounding rock can completely realize self-stability under the action of the initial support; the secondary lining, as a safe reserve, is not the second lining without force, but the second lining force can be neglected compared with its bearing capacity. The main function of the second lining is to improve the durability of the composite lining structure and to resist the possible deterioration of surrounding rock. The self-bearing capacity of surrounding rock is paid more and more attention in the design and construction of tunnel engineering nowadays. The surrounding rock and support are regarded as a unity to bear the load. In order to fully realize the self-supporting capacity of surrounding rock, we can allow the surrounding rock to have certain deformation in tunnel excavation and later period, and give full play to the self-supporting capacity of surrounding rock, which will also reduce the function of surrounding rock to the supporting structure at the same time. The stress state of surrounding rock is improved effectively. In order to prevent the deformation of the surrounding rock from entering into loose state and to meet the need of the secondary lining to play its role within a reasonable range, the supporting time must be reasonable. If the support is premature, the stress of surrounding rock can not be released, and the load applied on the second lining is too large, the secondary lining must be required to have higher stiffness and strength, and at the same time, there will be larger hidden dangers of safety, such as too late support, the displacement of surrounding rock can not be restricted. The second liner will be subjected to more pressure because of the failure of surrounding rock, and the displacement will be too large. Therefore, the selection of a reasonable supporting time has become the focus of tunnel engineering.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U455.7
[Abstract]:Since entering 21 century, our country economy construction speed has improved obviously, has obtained the unprecedented development. Economic development brings the demand of transportation. Therefore, the construction of high-speed railway in China has made great progress in recent years. The construction of high-speed railway requires the construction of tunnels. In the actual project, due to the slow construction progress of the tunnel itself, many tunnel projects will become the control project of the whole high-speed railway tunnel. Although the time limit, quality and safety of the tunnel can be guaranteed well under the condition of good geology, in some cases of poor geological conditions, such as large deformation of soft rock with high ground stress, Because of the large deformation of surrounding rock, the construction period is prolonged, the safety is decreased and the cost is increased. In the long-term research, the idea that the initial support bears all the load and the secondary lining as the safety reserve is deeply accepted. The initial support bears all the loads, which means that the surrounding rock can completely realize self-stability under the action of the initial support; the secondary lining, as a safe reserve, is not the second lining without force, but the second lining force can be neglected compared with its bearing capacity. The main function of the second lining is to improve the durability of the composite lining structure and to resist the possible deterioration of surrounding rock. The self-bearing capacity of surrounding rock is paid more and more attention in the design and construction of tunnel engineering nowadays. The surrounding rock and support are regarded as a unity to bear the load. In order to fully realize the self-supporting capacity of surrounding rock, we can allow the surrounding rock to have certain deformation in tunnel excavation and later period, and give full play to the self-supporting capacity of surrounding rock, which will also reduce the function of surrounding rock to the supporting structure at the same time. The stress state of surrounding rock is improved effectively. In order to prevent the deformation of the surrounding rock from entering into loose state and to meet the need of the secondary lining to play its role within a reasonable range, the supporting time must be reasonable. If the support is premature, the stress of surrounding rock can not be released, and the load applied on the second lining is too large, the secondary lining must be required to have higher stiffness and strength, and at the same time, there will be larger hidden dangers of safety, such as too late support, the displacement of surrounding rock can not be restricted. The second liner will be subjected to more pressure because of the failure of surrounding rock, and the displacement will be too large. Therefore, the selection of a reasonable supporting time has become the focus of tunnel engineering.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U455.7
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