3 results about "Limit analysis" patented technology

The application discloses a kind of minimum safety distance determination method and system of tunnel excavation face crossing gob area, method includes the following steps: set the failure mode of tunnel excavation face instability under the condition that coal mine gob area is contained in stratum, and establish theoretical model based on failure mode;Minimum safety distance condition is judged based on theoretical model;The shape of the failure region is optimized, and the optimal solution of minimum safety distance is obtained based on minimum safety distance condition.The application proposes a failure mode suitable for the instability of tunnel excavation face crossing coal mine gob area, and the analytical solution of minimum safety distance is derived using the upper bound method of limit analysis.Compared with numerical simulation and analytical solution, the model proposed by the application has high precision and can reflect the mechanism of tunnel excavation face instability and failure.

This invention discloses a simplified analysis method for the heave stability of unsaturated foundation pits. Addressing the heave stability problem of unsaturated foundation pits, a simplified analysis method based on the upper limit principle of limit analysis is proposed. The Prandtl failure mechanism is used to assess the heave stability of the foundation pit, calculating the velocity field of all sliding soil masses and the external power exerted by soil gravity. Based on the velocity field of the sliding soil masses, the total energy dissipation rate caused by the apparent cohesion of the unsaturated soil is calculated, and the safety factor for the heave stability of the foundation pit is obtained based on the principle of increased unit weight. Compared with existing technologies, this invention effectively combines the unsaturated soil strength theory with the limit analysis method, providing a reasonable explanation for the strengthening mechanism of suction effect in the heave stability problem of foundation pits. This has practical guiding significance for the design and excavation of foundation pits under complex conditions.

This application discloses a method for predicting the strong seismic stability of high mountains, relating to the field of rock mass engineering geological dynamics. The method includes: constructing a two-dimensional model of the target mountain; determining the sliding surface of the two-dimensional model; dividing the two-dimensional model into multiple sliding body elements based on the sliding surface; constructing a permissible sliding velocity vector field for the two-dimensional model; calculating the external force power and internal energy dissipation of the two-dimensional model based on the permissible sliding velocity vector field and the internal structural surface strength parameters of the two-dimensional model after freeze-thaw cycle degradation; and predicting the strong seismic stability of the target mountain based on the external force power and the internal energy dissipation. This method solves the problem that existing limit analysis upper bound methods generally do not fully consider the synergistic effect of freeze-thaw cycles and fissure water seepage, leading to difficulties in accurately predicting the strong seismic stability of high mountains.