Stability Analysis Of Foundation With Opening In Layered Rock Masses

With social development and fast-paced urbanization, compressive use of floorspace and underground space become a development priority. In Chong Qing, there aremany high buildings and varieties of underground architectures such as bomb shelters,subway tunnels, and largeunderground shopping centers and so on. In the developmentof society, it is normal that some of these buildings will be converted, dismantled, orrebuilt. However, because of the existence of underground architectures, these projectsbecome complex for that it is necessary to consider the safety and normal use of sur-face structures and underground structures at the same time as two factors are inter-linked, that it is the problem of the stability of foundation with caverns. Meanwhile,the layered rock which accounts for2/3of land areas made these engineering morecomplicated as its highly complicated mechanism properties and failure properties.Therefore, this paper analyzes the stability of foundation with opening in layeredrock masses and the influence of the physics and mechanics parameters of joints andthe locations of surface buildings loads on the stability by using Ubiquitous-Joint con-stitutive model with Fast Lagrangian Analysis of Continua which can reflect the cha-racteristic of layered rock masses better and be easy to applied in the practical engi-neering. Through analysis, the main results in the paper are as follows:①From the perspectives of theory and practice, the instability mechanism andfailure mode of tunnel in layered rock is analyzed and summarized which indicates thefailure mode is closely related to the property of beddings, such as the dip angle ofbedding. Since the stability of cavernfoundation consists of the stability of tunnel andbuildingfoundation, this paper respectively concludes the stability criteria of tunnel andbuilding foundation and makes them both be stability criteria of cavern foundation as awhole.②Constitutive models of layered rock are summarized and being compared thatshows the Ubiquitous-Joint model reflects the anisotropy an failure mode of surround-ing rock of tunnel in layered rock. Thus this paper choose Ubiquitous-Joint model toanalyze the stability of cavern foundation in layered rock.③Comparing the results calculated with Mohr-Coulomb model and that withUbiquitous-Joint model that shows that the Ubiquitous-Joint model can better reflectthe anisotropy of layered surrounding rock. In addition,carry out dynamic analysisby applying the building load and changing its position which shows the position ofloads have some influence on the stress and deformation of craven foundation.④The influence of physics and mechanics parameters of beddings on settlementsat vaults and surface and relative displacements of sidewall are studied by using or-thogonal test design. Besides, with the results of the test, the influences of property ofbeddings on displacements are concluded that indicates the parameters of beddinghave a greater impact on the displacement of carven foundation.⑤Analyze the stability of cavern foundation when building structures on the sur-face with working tunnel in the foundation with Ubiquitous-joint model. And a com-parison of the results to the monitoring data is done that proved the calculation andmonitoring data are consistent to each other.