| With the increase of urban land use rate in China,the demand for municipal pipelines is increasing.Underground pipeline corridor emerged as the times require.As an underground structure to solve the problem of insufficient space above ground,underground comprehensive pipeline corridor provides convenience for people and maximizes land use efficiency.Shield tunneling for underground structures is also a common construction method now.Shield tunneling is used to prevent soil and sand collapse on the excavation surface,while excavating and lining safely in the machine,so as to construct a tunnel construction method.However,the research on underground shield tunneling structure is rare.The purpose of this paper is to study the ground vibration of underground pipe gallery with shield tunneling.The dynamic characteristics of common pipe gallery and shield tunnel gallery are compared and analyzed.Referring to the research results of scholars at home and abroad,using finite element simulation software ABAQUS,the common pipe gallery model and shield tunnel underground pipe gallery model are established.When calculating,it is divided into two calculation steps,which not only simulate the geostress balance step,but also simulate the ground motion.El seismic wave is selected to calculate and analyze the seismic response of the structure system under 0.1g peak value 0.2g peak value 0.4g peak acceleration,and the influence of different soil elastic modulus and concrete strength on the corridor under 0.1g peak value.The main contents of this paper include:Firstly,based on the characteristics of the shield-driven underground pipeline gallery and analysis software ABAQUS,Mohr-Coulomb constitutive model is adopted for the soil,plastic damage constitutive model for concrete,and the contact between soil and underground structure is adopted for software-borne contact,selection of artificial boundary and input of ground motion,and infinite element artificial boundary is adopted to solve the problem of selection and input of ground motion.The whole model of the underground pipeline Gallery system.Secondly,this paper chooses two models of common pipe gallery and shield tunnel gallery to carry out comparative analysis under the 0.1 peak value.For the two analysis steps that need to be calculated in this paper,the first one is the static analysis step of in-situ stress balance,and the second one is the seismic analysis step.Finally,according to the actual site and specifications,the El seismic wave with peak acceleration of 0.1g.0.2g.0.4g and site characteristic period of 0.35s is selected as the dynamic load time history of seismic input for the two models of common pipe gallery and shield tunnel gallery,and the effects of different soil elastic modulus and concrete strength on the structure of shield tunnel Gallery at peak value of 0.1g are compared.The research results show that under the action of horizontal earthquake,complex structure-foundation dynamic interaction will occur between segment concrete structure and surrounding rock and soil.During the process of seismic action,a series of complex non-linear contact phenomena,such as contact-opening-contact-opening,will occur between segment concrete and surrounding soil.Through the dynamic time at the four positions of vault,arch bottom and left and right side walls,a series of complex non-linear contact phenomena will occur.The analysis of path curve and mechanical response at typical time shows that different peak acceleration and elastic modulus of soil have greater influence on the corridor. |
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