外文资料翻译---柔弱岩石上短距离隧道的动态施工力学的研究-公路隧道(编辑修改稿)

外文资料翻译---柔弱岩石上短距离隧道的动态施工力学的研究-公路隧道(编辑修改稿)内容摘要：

dimension FEM elastoplastic and viscoelastoplastic analyses to tunnel excavation(AN, 1994, XIAO, 2020 amp。 ZHU et al., 1996).In the aspect of the research in the tunnel of small distance, LIU et al. (2020) carried out the tests on Zhaobaoshan tunnel, which is the first super small distance tunnel in China. WAN et al. (2020) made specifically the concept of small distance tunnel. JIN et al. (2020) discussed the adaptability of the construction methods through the numerical simulating. YAN et al. (2020) analyzed the mechanical characteristic and deformation rules of the supports in different construction methods. LIU et al. (2020) introduced the design scheme of highway tunnel of small distance with 8 lanes. Most of studies mentioned above were aimed separately at construction characters of the tunnel in soft and weak 7 rocks 117 Modern Applied Science and the parison and selection of the construction schemes of small distance tunnel. The discussion bining the two aspects is less made, so it’s necessary to study the dynamic construction mechinics characteristic of small distance tunnel in soft and weak rocks. 2. Engineering General Situation Engineering Geology The geological survey shows that the bottom, the tunnel mostly get through, is the Jurassic upper Shaximiao, and the underlying bedrock is the interbedded of mudstone and sandstone. The strike direction of the strata intersect the tunnel axis to 85176。 , the strata dip angle is about 9176。 , the bination between the layers of rock is general, and the level of rock is grade V. The groundwater is poor, and the main form of the water in tunnel is damp or dripping. The saturated uniaxial pressive strength of mudstone Rc=, Integrity factor Kv=, K1=, K2=, K3=0, [BQ]=219. The saturated uniaxial pressive strength of Sandstone Rc=, integrity factor Kv=, K1=, K2=, K3=0, [BQ]=319. The surface of geological structure is very developed, the rock body is extremely fragmented, and the block strength is not strong. So it belongs to the typical category of the soft and weak rocks. Engineering Construction Method The double sidewalls construction method is guided under the supporting role with advanced small pipe, in order to reduce the influence of tunnel construction on the highway operations, ensure the safety of tunnel construction. The outside radius of advanced small pipe is Φ42mm, the length is and the circumferential spacing is 40cm. In the construction process, the excavation length is controlled strictly, the primary support is constructed every 4m, and the 30cm thick closed loop of steel concrete is molded between the secondly lining and primary support. The bolts are the forms of hollow grouting and quincunx layout, the diameter and length are setted as 25mm and , the vertical and circumferential spacing are located 200cm and 80cm apart. The primary support and secondly lining are forms of the 28cm thick C20 shotcrete and 60cm thick C25 model reinforced concrete. 3. NumericalModel The tunnel length in simulating model is selected as 20m, and the model has 21850 elements, in which bolts have 3850 elements(). The tunnel surrounding rock is considered to be elastoplastic material. Because the mechanics characteristic of the support structure is better than the surrounding rock, so it could be regarded as elastic material. The effect of steel arch shelf in shotcrete and advanced small pipe could be simulated using equivalent method. is the basic mechanics parameter of the material. In order to ensure the veracity of calculation, the model dimension can be set as : left and right are all 50m, vertical to earth surface, down is 8 50m. 4 Results Analysis Surface Subsidence Analysis The surface subsidence should be strictly contr。