發(fā)布時(shí)間：2018-08-30 19:09

【摘要】：無(wú)粘結(jié)環(huán)錨預(yù)應(yīng)力混凝土襯砌結(jié)構(gòu)是應(yīng)用在水工隧洞中的一種新型結(jié)構(gòu)形式，該結(jié)構(gòu)主要適用于襯砌圍巖地質(zhì)條件較差，襯砌中的水壓力較大，以及襯砌產(chǎn)生開(kāi)裂之后水滲入圍巖導(dǎo)致周?chē)ㄖ锸Х�(wěn)的水工隧洞結(jié)構(gòu)中。作為一種新型的結(jié)構(gòu)形式，無(wú)粘結(jié)預(yù)應(yīng)力混凝土襯砌具有其特殊的優(yōu)點(diǎn)：襯砌中鋼絞線(xiàn)采用雙圈環(huán)繞的形式，使襯砌中的壓應(yīng)力分布更加均勻，錨索的沿程預(yù)應(yīng)力損失更小，與有粘結(jié)襯砌相比有效預(yù)壓應(yīng)力增大，因此襯砌的厚度可以適當(dāng)減小，這樣就能夠節(jié)省材料，減小開(kāi)挖量，降低施工的難度和工程造價(jià)，有效的加快施工進(jìn)度。鑒于無(wú)粘結(jié)環(huán)錨預(yù)應(yīng)力混凝土襯砌具有的優(yōu)勢(shì)，這種結(jié)構(gòu)在我國(guó)水工隧洞中有著廣闊的應(yīng)用前景。黃河小浪底排沙洞是我國(guó)第一例采用無(wú)粘結(jié)雙圈環(huán)繞預(yù)應(yīng)力混凝土襯砌這種結(jié)構(gòu)形式的水工隧洞。 在施工階段，小浪底排沙洞中埋設(shè)了混凝土應(yīng)變計(jì)、鋼筋計(jì)、無(wú)應(yīng)力計(jì)、錨索測(cè)力計(jì)、滲壓計(jì)和測(cè)縫計(jì)等154支觀(guān)測(cè)儀器。小浪底排沙洞從1997年施工，1999年投入運(yùn)行，使用至今已十幾年。在此期間，排沙洞經(jīng)歷了各種設(shè)計(jì)工況的考驗(yàn)。工程中所埋設(shè)的觀(guān)測(cè)儀器積累了數(shù)萬(wàn)組觀(guān)測(cè)數(shù)據(jù)。本文對(duì)這些采集的數(shù)據(jù)進(jìn)行了系統(tǒng)的整理分析，以了解小浪底工程排沙洞在施工與運(yùn)行過(guò)程中混凝土襯砌應(yīng)力、應(yīng)變發(fā)展變化的規(guī)律，從而判斷結(jié)構(gòu)是否合理和安全。 本文應(yīng)用ANSYS有限元分析軟件對(duì)小浪底排沙洞進(jìn)行建模分析，分別對(duì)錨索張拉階段的施工期和加水壓后的運(yùn)行期的襯砌應(yīng)力狀態(tài)進(jìn)行分析，并將結(jié)果與監(jiān)測(cè)數(shù)據(jù)進(jìn)行對(duì)比，看出兩者具有很好的一致性。結(jié)果表明，在整個(gè)襯砌結(jié)構(gòu)中，錨具槽部位的受力狀態(tài)是最復(fù)雜的，最大最小環(huán)向應(yīng)力均出現(xiàn)在錨具槽附近，軸向和徑向還出現(xiàn)了較小的拉應(yīng)力。 針對(duì)在小浪底排沙洞襯砌施工和運(yùn)行過(guò)程中暴露出的問(wèn)題，尤其是錨具槽部位的漏油等現(xiàn)象，本文對(duì)小浪底排沙洞環(huán)錨預(yù)應(yīng)力混凝土襯砌的結(jié)構(gòu)設(shè)計(jì)方案、預(yù)應(yīng)力筋的布置以及錨具槽的布置等內(nèi)容進(jìn)行優(yōu)化設(shè)計(jì)，，并采用有限元軟件模擬分析。研究結(jié)果表明：優(yōu)化后的結(jié)構(gòu)薄弱區(qū)范圍明顯減小，錨具槽附近的應(yīng)力分布更均勻，具有明顯的經(jīng)濟(jì)效益，對(duì)于今后的工程具有一定的參考價(jià)值。 根據(jù)實(shí)測(cè)數(shù)據(jù)和模擬結(jié)果對(duì)整個(gè)無(wú)粘結(jié)預(yù)應(yīng)力排沙隧洞段的安全使用狀態(tài)進(jìn)行評(píng)價(jià)分析，采用定性與定量結(jié)合的方法，并主要通過(guò)錨索測(cè)力計(jì)的監(jiān)測(cè)數(shù)據(jù)、滲壓計(jì)的監(jiān)測(cè)數(shù)據(jù)、襯砌混凝土的應(yīng)力狀態(tài)這三個(gè)指標(biāo)進(jìn)行安全評(píng)價(jià)分析。結(jié)果表明，通過(guò)安全評(píng)價(jià)，認(rèn)為排沙洞能保證正常使用，不會(huì)出現(xiàn)開(kāi)裂和滲漏。文中建立的小浪底排沙洞施工和運(yùn)行過(guò)程中的安全狀態(tài)預(yù)警預(yù)報(bào)系統(tǒng)，可以對(duì)今后類(lèi)似工程的設(shè)計(jì)優(yōu)化和這種新型結(jié)構(gòu)的推廣使用提供依據(jù)。
[Abstract]:The unbonded ring anchor prestressed concrete lining structure is a new type of structure used in hydraulic tunnel. The structure is mainly suitable for the poor geological conditions of the surrounding rock of the lining and the high water pressure in the lining. And the structure of hydraulic tunnel where water seeps into surrounding rock and causes instability of surrounding buildings after cracking of lining. As a new type of structure, unbonded prestressed concrete lining has its special advantages: the steel strand in the lining is surrounded by double loops, which makes the distribution of compressive stress in the lining more uniform and the loss of prestress along the cable less. Compared with the bonded lining, the effective precompression stress increases, so the thickness of the lining can be reduced appropriately, which can save the material, reduce the amount of excavation, reduce the difficulty of construction and project cost, and effectively accelerate the construction progress. In view of the advantages of unbonded ring anchor prestressed concrete lining, this kind of structure has a broad application prospect in hydraulic tunnels in China. Xiaolangdi sand discharge tunnel of the Yellow River is the first hydraulic tunnel in China with unbonded double-ring surrounding prestressed concrete lining. In the construction stage, 154 observation instruments, such as concrete strain gauge, steel bar meter, non-stress gauge, anchor cable dynamometer, pressure gauge and joint gauge, are embedded in the Xiaolangdi sand discharge tunnel. Xiaolangdi sand drainage tunnel was constructed in 1997 and put into operation in 1999. It has been used for more than ten years. During this period, the sand drainage tunnel has experienced the test of various design conditions. The observation instruments embedded in the project have accumulated tens of thousands of observation data. In this paper, the collected data are systematically analyzed in order to understand the development and variation of concrete lining stress and strain during the construction and operation of the sand drain tunnel of Xiaolangdi Project, and to judge whether the structure is reasonable and safe. In this paper, ANSYS finite element analysis software is used to model and analyze the sand discharge tunnel in Xiaolangdi. The stress state of lining during the construction period of the tension stage of the anchor cable and the running period after adding water pressure are analyzed respectively, and the results are compared with the monitoring data. We can see that there is a good consistency between the two. The results show that the stress state of the slot is the most complex in the whole lining structure, the maximum and minimum circumferential stress appear near the Anchorage slot, and the axial and radial tensile stresses are smaller. In view of the problems exposed during the construction and operation of the Xiaolangdi sand drainage tunnel, especially the leakage of the Anchorage slot, the structural design scheme of the prestressed concrete lining for the ring anchor of the Xiaolangdi sand drain tunnel is presented in this paper. The layout of prestressing tendons and the arrangement of anchors are optimized, and the finite element software is used to simulate the design. The results show that the weak area of the optimized structure is obviously reduced, the stress distribution near the Anchorage slot is more uniform, and it has obvious economic benefit, which has certain reference value for the future engineering. According to the measured data and simulation results, the safe operation state of the whole unbonded prestressed sand discharge tunnel is evaluated and analyzed. The qualitative and quantitative methods are adopted, and the monitoring data of the anchor cable dynamometer and the osmotic pressure meter are mainly used. The stress state of lining concrete is evaluated and analyzed. The results show that, through safety evaluation, it is considered that sand drainage holes can be used normally without cracking and leakage. The early warning and prediction system of the safety state in the construction and operation of Xiaolangdi sand drainage tunnel can provide the basis for the design optimization of similar projects and the popularization and application of this new structure in the future.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TV332

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本文編號(hào)：2214021