The article presents comparative geotechnical calculations using the Plaxis software package and the LIRA 10 Installation, Filtration, and Physical nonlinearity modules.
Author: Melentiev Alexey
The task was to check the correctness of geotechnical calculations using Installation, Filtration, and Physical nonlinearity modules of the LIRA 10 software package.
The project of the adaptation of the historic building for modern use as a hotel was taken as the initial data. The project was developed taking into account the requirements of the current legislation on the preservation of the special aspects of the cultural heritage object.
The geotechnical part of the project was calculated in the Plaxis software package.
The existing building has three floors, a basement, and an attic. The project also proposes the construction of underground parking lots under the courtyard. It is their construction that determines the impact on the surrounding soil body. The geotechnical calculation is performed without taking into account additional measures for reinforcement and preservation of the existing foundations of the building.
The slurry wall with a length of 26 m and a thickness of 800 mm is taken as the enclosing structure. The excavation pit has a depth of about 5.5 m. It is excavated in a cut-and-cover way with one level of struts.
For an adaptable building that is an architectural monument and an object of the cultural heritage of federal significance and is related to the II category of technical condition, according to Appendix E SP 22.13330.2016 maximum additional yield is 1.5 cm and relative differential settlement is 0.0010.
Loads: dead weight and, respectively, active and passive earth pressure, hydrostatic pressure on the enclosing structure.
Table.1. shows the results of the calculations. The table doesn’t contain the results obtained without the use of modules.
Calculation results without modules
Calculation results with modules
Additional yield exceeds the limit and additional measures are needed to compensate or reduce them.
Table 1. Comparison of the results.
|
Stress-strain behaviour |
LIRA 10 |
Plaxis |
|
Additional yield of the existing building, cm |
5,7 |
4,9 |
|
Bending moment of slurry wall 800 mm thick, kNm |
826 |
857 |
Thus, similar parameters of the additional yield of the existing building and the forces in the enclosing structure were obtained when using the Mohr-Coulomb theory (MC) in Plaxis and LIRA 10 computing complexes (using Physical nonlinearity, Installation, and Filtration modules).
This allows you to use LIRA 10 (with the modules) in the geotechnical design of temporary and structures of a reduced importance class and to perform the calculation of retaining walls and shallow pits.
