Abstract
In situ stress state is a predominant factor for the design and safe construction of geotechnical engineering. For a real construction site, the amount of calculation using a finite element method for in situ stress field increases dramatically with the increase of the calculation freedom due to large-scale uncertainties. In order to reduce the computing cost without losing the accuracy of the calculation, an optimization algorithm combined with a reduced order model, which is realized by the proper orthogonal decomposition algorithm (POD) for large-scale in situ stress field, is put forward in this paper. The POD algorithm produces a set of orthogonal bases through the extraction of the field variables, combining with the Galerkin finite element method to create a reduced order numerical model. The reduced order model is then calculated with a global optimization algorithm to inversely find the solution for the actual in situ stress field. In order to verify the accuracy and efficiency of the method, two examples are presented to simulate the inverse calculation of the in situ stress field. They showed that the computation time of the POD method could reach 1/10 of the ordinary computation time. Also, the results showed good accuracy with a minimum computational expense, which can provide a reference for inverse calculation of large-scale in situ stress field.
Highlights
Many rock engineering processes, especially deep mining and slope, are carried out in complex geological bodies and geological environments [1,2,3,4]
One is relied on the displacement measured data with consideration of mechanical characteristics of the local rock mass to calculate the quantity and direction of in situ stress [8]; the other is according to the measured stress of certain control points in actual engineering site, creating a numerical model considering topography and geology, lithology, and so on, using an inverse algorithm to calculate the in situ stress field [9]
E core problem of inverse calculation of in situ stress field can be recast as an optimization problem, which is to construct a group of boundary conditions applied to the numerical model to generate the calculated stress, the error between the calculated stress and the measurement stress is minimum. erefore, the objective function for optimization is as follows:
Summary
For a real construction site, the amount of calculation using a finite element method for in situ stress field increases dramatically with the increase of the calculation freedom due to large-scale uncertainties. In order to reduce the computing cost without losing the accuracy of the calculation, an optimization algorithm combined with a reduced order model, which is realized by the proper orthogonal decomposition algorithm (POD) for large-scale in situ stress field, is put forward in this paper. E reduced order model is calculated with a global optimization algorithm to inversely find the solution for the actual in situ stress field. The results showed good accuracy with a minimum computational expense, which can provide a reference for inverse calculation of large-scale in situ stress field
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
