隧道盾构毕设论文外文中英文翻译中英文翻译原文.docx

毕业设计（论文）外文文献翻译院系：土木工程与建筑系年级专业：土木工程姓名：学号：附件：盾构SHIELDSS HIELDS【Abstract】Atunnelshieldisastructuralsystem,usedduringthefaceexcavationprocess.Thepapermainlydiscussestheformandthestructureoftheshield.Propulsionfor the shield is provided by a series of hydraulic jacks installed in the tailof the shieldandtheshieldiswidespreadusedintheundergroundenvironmentwherecannotbeinlongtimestable.Themainenemy oftheshieldisgroundpressure.Non-uniformgroundpressurecausedbythesteeringmayactontheskintendstoforcetheshieldofflineandgrade.Andworkingdecksinsidetheshieldenabletheminerstoexcavatetheface,drilland loadholes.【Keywords】shieldhydraulic jacks ground pressure steering workingdecksA tunnel shield is astructural system, normally constructed of steel, used duringthefaceexcavationprocess.Theshieldhas anoutsideconfigurationwhichmatchesthetunnel. The shield provides protection for the men and equipment and also furnishedinitial ground support until structural supports can be installed within the tail section oftheshield.Theshieldalsoprovidesareactionbaseforthebreast-boardsystemusedtocontrol face movement. The shield may have either an open or closed bottom. Inaclosed-bottomshield,theshieldstructure andskin provide 360-degree ground contactandthe weightoftheshieldrests upontheinvertsectionoftheshieldskin.Theopenshield has no bottom section and requires some additional provisionis a pair of sidedrifts driven in advance of shield excavation. Rails or skid tracks are installedwithinthese side drifts to provide bearing support for the shield.Shield length generally varies from1/2 to 3/4 of the tunnel diameter. The front ofthe shield is generally hooded to so that the top of the shield protrudes forwardfurtherthan the invert portion which provides additional protection for the men working attheface and also ease pressure on the breast-boards. The steelskin of the shield mayvaryfrom1.3 to 10 cm in thickness, depending on the expected ground pressures.