Excavation Deformation Research Articles

Study on Deformation Characteristics of Deep Foundation Excavation in Soft-Soil and the Response of Different Retaining Configurations

In recent years, many researchers have considered the mechanical characteristics of deep foundation excavation in soft-soil. The analysis of these deep excavations requires consideration of an uncertain, nonlinear, dynamic and complicated system, and involves consideration of soil strength, stability, deformation, fluid flow and interaction of soil and different retaining configurations. It is difficult to describe such a nonlinear system using traditional analysis. Therefore, in order to accurately describe the mechanical behavior of a representative deep excavation of the subway station, in this case, 3-Dimensional geotechnical numerical analysis method using FLAC3D software was applied. Using this tool, a study considering earth pressure, soil deformation and settlement was carried out. Furthermore, the response of different retaining configurations was deeply investigated. Triaxial cement mixing piles were considered as a way to optimize deformation of the deep excavation and reduce settlement of the ground surface and the railway embankment. The analysis indicated that the deeper the foundation excavation was, the larger the surface settlement and the smaller the earth pressure. The analysis also considered the mechanical effect of varying the wall thickness and the wall depth on the structure‘s deformation characteristics. The simulations indicated that a wall thickness of less than 1.4 m effectively reduced wall horizontal displacement, ground surface settlement and uneven settlement of railway embankment. While a variable wall embedded depth that was less than 52 m also changed the settlement of the excavation deformation and the ground surface. Therefore, the numerical results can agree with the practical project to imply that numerical method in the paper is applicable and reliable, which provides a new thought to research on deep excavation in soft-soil.

Excavation Deformation Analysis of Deep-Cutting High Rock Slope

The mainly purpose of the paper is to investigate the slope excavation deformation of the rock slope at the deep-cutting valley under different load conditions. As an example of the rock slope at the intake of the sluice tunnel of Jinping hydropower station, whose slope deformation characteristics was system analyzed by numerical method during different construction conditions. The dead weight, rain, seism and theirs combination were involved in the numerical analysis. The numerical results could give a reference for the excavation stability of the high rock slope, and it is the basis to determine the reasonable construction method and to optimize the design of the strengthening and enhancing engineering.

Study for Deformation Control Technology of Bottom Slope of Conveyor Belt in Open Pit Mine

Deformation of slope for all section is almost the same while the width of slope along the strike is large enough, that is plane deformation. If the width is small, then cannot analyze according to the plane problem. According to above method, slope deformation of concave base is 3D problem if excavates a limited width concave conveyor belt alone the slope dip in open-pit mine. In this article, the relation between excavation width and deformation is analyzed by 3D numerical simulation method, on the basis of some mine actual geological occurrence conditions, meanwhile, calculative equation among deformation geometry and limit equilibrium is established to evaluate concave base slope stability. Concave base slope for conveyor belt is 32% for deformation of plane mode slope in light of numerous simulation result, and the stability coefficient can be improved by 0.5 through case studies analysis. So, the safety of belt transport system is ensured.

Research on Prediction of Excavation Deformation Based on Fuzzy Neural Network

Seeing that there are a lot of uncertain and fuzzy factors in the deformation control system of excavation, in this paper, the author combined the fuzzy theory with neural network technology, adopted the ordinary non-linear structure as the fuzzy neural network of neural network structure formed of neuron directly, and it is under the degree fuzzy number which inputs and export the information to import the corresponding network. Thus according to fuzzy neural network, displacement prediction model has been set up.

Analysis of the Dynamic Performance of an Underground Excavation in Jointed Rock under Repeated Seismic Loading

Results from field observations of dynamic behaviour of an underground excavation have been compared with numerical studies of the rock deformation history. The field behaviour shows progressive accumulation of rock displacement and excavation deformation under successive episodes of dynamic loading. It is possible to reproduce the modes of rock response quite well using a Distinct Element model of the rock mass, but the way displacements develop is dependent on the joint model used in the analysis. It is suggested that, in rock masses subject to repeated dynamic loading, excavation design may need to take account of the prospect of repeated episodes of transient loading at the excavation site.