【正文】 土釘?shù)淖饔脵C(jī)理　　土釘在復(fù)合土體內(nèi)的作用有以下幾點(diǎn)： 　　（1） 土釘對(duì)復(fù)合土體起箍束骨架作用制約土體變形并使復(fù)合土體構(gòu)成一個(gè)整體。不僅效地提高了土體的整體剛度，彌補(bǔ)了土體抗拉、抗剪強(qiáng)度低的弱點(diǎn)。土釘墻技術(shù)則是在土體內(nèi)放置一定長(zhǎng)度和分布密度的土釘體與土共同作用，彌補(bǔ)土體自身強(qiáng)度的不足。土釘墻的基本原理土釘墻的作用原理　　土體的抗剪強(qiáng)度較低，抗拉強(qiáng)度幾乎可以忽略，但土體具有一定的結(jié)構(gòu)整體性，在基坑開挖時(shí)，可存在使邊坡保持直立的臨界高度，但在超過這個(gè)深度或有地面超載時(shí)將會(huì)發(fā)生突發(fā)性的整體破壞。 　?。?） 不適用于沒有臨時(shí)自穩(wěn)能力的淤泥土層，流朔狀態(tài)的軟粘土保持成孔時(shí)的孔壁的穩(wěn)定比較困難且界面摩阻力很低，技術(shù)經(jīng)濟(jì)效益不理想，因此也不宜采用。 　?。?） 對(duì)于朔性指數(shù)Ip20的土，必須注意仔細(xì)評(píng)價(jià)其蠕變特性后方可采用。 　?。?） 適用于地下水位低于開挖層或經(jīng)過降水使地下水位低于開挖標(biāo)高的情況。 　?。?） 土釘墻本身變形很小，對(duì)相鄰建筑物影響不大。 　?。?） 土釘墻成本費(fèi)較其他支護(hù)結(jié)構(gòu)顯著降低。 　?。?） 隨基坑開挖逐層分段開挖作業(yè)，不占或少占單獨(dú)作業(yè)時(shí)間，施工效率高，占用周期短。1979年巴黎國(guó)際土加固會(huì)議之后在西方得到廣泛應(yīng)用，1990年在美國(guó)召開的擋土墻國(guó)際學(xué)術(shù)會(huì)議上，土釘墻作為一個(gè)獨(dú)立的專題與錨桿擋墻并列，使它成為一個(gè)獨(dú)立的土加固學(xué)科分支 土釘墻的特點(diǎn)與應(yīng)用范圍土釘墻應(yīng)用于基坑開挖支護(hù)和挖方邊坡穩(wěn)定有以下特點(diǎn)： 　?。?） 形成土釘復(fù)合體、顯著提高邊坡整體穩(wěn)定性和承受邊坡超載的能力。 60年代出現(xiàn)了加筋土墻，一般在填方區(qū)如筑路、平整場(chǎng)地填方區(qū)域形成的擋土墻，在分層回填土方時(shí)分層鋪放土工織物并于預(yù)制砼面板拉結(jié)，形成加筋土擋墻。土釘墻的發(fā)展50年代末期通過土層錨桿的使用使擋土結(jié)構(gòu)有了新發(fā)展，在基坑開挖前先建造樁、地下連續(xù)墻、板樁等利用土層錨桿對(duì)其進(jìn)行背拉從而形成錨桿式擋墻。土釘墻是通過鉆孔、插筋、注漿來設(shè)置的，一般稱砂漿錨桿，也可以直接打入角鋼、粗鋼筋形成土釘。. nail appropriate chooses Ⅱ, Ⅲ level gongs grain reinforced, the diameter 16 and 32, the hole diameter 70 ~ 120. layer injection concrete strength level shall not be lower than C20. shoot concrete surface thickness appropriate is 80 ~ 200, usually by 100. shot in concrete surface with steel mesh, the level I reinforced, diameter 6 ~ 10, span 150 ~ 300, reinforcement fabric lap length is more than 300. cement slurry materials net plasma or cement mortar, its strength is not less than M10. underground water level higher than the foundation pit bottom when, should adopt precipitation or cut water measures。s occurrence. The soil nailed wall of structural requirements: The metope of nailed wall slope shoulds not be greater than 10. 1. was exposed the end and the effective level connected together, put pressure plates and reinforcement. nail length appropriate for excavation depth ~ times, of nail spacing appropriate for ~ m, soil nail and horizontal Angle for 10 176。 Single soil nail at the garden arc sliding surface crack the solid and the limit of the soil anchor railroad cars/containers puting。t happen grain soil slope that sudden collapse slippery, the soil nailed wall not only delay plastic deformation stage of development, but also has the obvious incremental deformation and cracking destruction, won39。50 s through the paper deals with the soil retaining structure have a new development, in the foundation pit excavation pile built before, underground continuous wall, such as the use of sheet pile soil layer on the pull back to form the retaining wall. 10 years after the structure in the wall, it is to use concrete ponent are arranged in excavation in the process of surface soil layer, with anchor to pull back, this is a kind of can and engineers projects at the same time the way in the operations. In the s there the reinforced wall, be in monly fill zones such as road, land leveling fill form in the area of the retaining wall, in layered backfilling when reclaiming earthworks layered lay out the geotextiles and in TongMianBan prefabricated Rachel, formation of the retaining wall. In the 70 s the soil nailed wall, 1972 French contractor in the French Versailles city railway slope excavation is successful application. 1979 Paris international soil reinforcement after the conference in the west has been extensively applied, held in 1990 in the United States of the international conference on retaining wall, the soil nailed wall as a separate project and bolt for retaining wall, make it bee an independent soil reinforcement subject branch The soil nailed wall of the characteristics and application areas The soil nailed wall applied in excavation support and grade of slope stability has the following features: (1) forming soil nail plex, improve the overall stability of the slope and under the slope overloading the ability. (2) the construction equipment simple, because the nail than the length of the general much smaller, do not add prestressed so simple equipment. (3) along with the foundation pit excavation work by subsection, do not take or less homework time alone accounted for, construction efficiency is tall, take up the cycle is short. (4) construction do not need to take up the alone, the site is narrow, put slope difficulties, it is adjacent buildings demonstrate its advantages. (5) the soil nailed wall cost significantly lower than other supporting structure. (6) construction noise, vibration small, do not affect the environment. (7) the soil nailed wall itself deformation is very small, the impact is not big to adjacent buildings. The soil nailed wall application fields The soil nailed wall not only applied to temporary support structure, and also used in permanent structures, when applied to permanent structures, appropriate increase jet concrete surface layer thickness and due consideration of its beautiful, at present the soil nailed wall the application field of mainly has: (1) the foundation underpinning (2) the foundation pit retaining or shaft (3) the retaining wall slope (4) the slope stability (5) and bolt for the protection of the retaining wall with cant Drilling grouting soil nailing wall type of excavation way down step by step, every step for 1 ~ 2 meters high, in construction soil nail bar, concrete road surface spray, during the period of slope in the state without support needs to be able to keep independent stable, so is mainly applied in: (1) have certain of the bonding miscellaneous fill earth, cohesive soil, powder soil, loess and weakly cemented of soil slope. (2) application to underground water level below the excavation layer or after rainfall make underground water level elevation below the excavation. (3) for standard penetration and several (N) of soil slope under 10 strike by soil nail method usually don39。 學(xué)生（簽名）： 年 月 日外文翻譯CONCEPTThe soil nailed wall is made of natural soil through the soil nailed wall in situ reinforcem