I trust this message finds you well.
I'm reaching out to seek guidance on conducting a pushover analysis for a soil-tunnel system utilizing the "reaction acceleration method," as depicted in the attached image labeled "Pushover_method.jpg."
At begain, the approach involves initially subjecting the soil-tunnel system to a gravity analysis to derive its static response, encompassing parameters such as axial forces, bending moments, etc. In this setup, the bottom of the model is fixed in both the x and y directions, while the side of the model is constrained in the x direction.
Subsequently, the x constraint of the soil is released, while still fixed in the y direction. Then, an inverted triangle inertial force is applied to the soil domain in the form of a body force until structural failure occurs.
Both the gravity and pushover forces are applied using body forces in the y and x directions, respectively, as mentioned earlier, but they are applied at different stages. However, it appears that in opensees, the x- and y- body forces of an element are always applied at the same stage and constant. I am seeking guidance on how to apply these two different body forces at different stages and how to apply the inverted triangle x body force using STKO.
I've conducted a preliminary attempt using a simple soil model, and the results are also attached for reference.
Any assistance or insights you could provide on this matter would be greatly appreciated.
Warm regards,
Jiaxing
- Pushover_method.jpg (326.14 KiB) Viewed 1108 times