【Discussion of the Day】Utility Engineering – Water Resources and Hydropower – 20210507
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What is the effect of temperature loads on the stress and stability of arch dams? Answer: After the arch dam is closed, the dam body becomes a single unit. When the temperature of the dam body is higher than the temperature at the time of closure, that is, as the temperature rises, the arch expands and shifts upstream. The direction of the bending moments and shear forces resulting from this is opposite to that caused by the water level in the reservoir, but the direction of the axial force remains the same. When the temperature of the dam body is lower than the temperature at which the arch is sealed, that is, as the temperature drops, the arch ring contracts and shifts downstream. The direction of the bending moments and shear forces resulting from this is the same as that caused by the water level in the reservoir, but the direction of the axial force is opposite. Therefore, generally speaking, temperature drops are detrimental to the stress state of the dam, while temperature rises are detrimental to the stability of the dam shoulders. We welcome active participation in discussions; the system offers generous rewards for answering questions from VIP members! ! !
After sealing, the arch dam becomes a single unit. When the temperature of the dam body is higher than the sealing temperature, that is, as the temperature rises, the arch expands and moves upstream. The direction of the bending moments and shear forces resulting from this is opposite to that caused by the water level in the reservoir, but the direction of the axial force remains the same. (4 points) When the temperature of the dam body is lower than the temperature at which the arch is sealed, that is, as the temperature drops, the arch contracts and shifts downstream. The direction of the bending moments and shear forces resulting from this is the same as that caused by the water level in the reservoir, but the direction of the axial force is opposite. Therefore, generally speaking, temperature drops are detrimental to the stress state of the dam, while temperature rises are detrimental to the stability of the dam shoulders.
After sealing, the arch dam becomes a single unit. When the temperature of the dam body is higher than the sealing temperature, that is, as the temperature rises, the arch expands and moves upstream. The direction of the bending moments and shear forces resulting from this is opposite to that caused by the water level in the reservoir, but the direction of the axial force remains the same. (4 points) When the temperature of the dam body is lower than the temperature at which the arch is sealed, that is, as the temperature drops, the arch contracts and shifts downstream. The direction of the bending moments and shear forces resulting from this is the same as that caused by the water level in the reservoir, but the direction of the axial force is opposite. Therefore, generally speaking, temperature drops are detrimental to the stress state of the dam, while temperature rises are detrimental to the stability of the dam shoulders.
After the arch dam is closed, the dam body becomes a single unit. When the temperature of the dam body is higher than the temperature at the time of closure, that is, as the temperature rises, the arch expands and shifts upstream. The direction of the bending moments and shear forces resulting from this is opposite to that caused by the water level in the reservoir, but the direction of the axial force remains the same. When the dam temperature falls below the arch-closing temperature, i.e., when the temperature decreases, the arch contracts and displaces downstream. The directions of the resulting bending moment and shear force are the same as those induced by the reservoir water level; however, the direction of the axial force is opposite. Therefore, under normal circumstances, temperature has an adverse effect on dam stresses, and temperature rise is detrimental to the stability of the dam shoulders.
The thermal load on arch dams affects both their stability and stresses; an increase in temperature is beneficial to stresses but detrimental to stability.
Arch dams are highly indeterminate structures, and temperature changes have a significant impact on both the deformation and stresses of the dam body. The magnitude of the temperature load is related to the closing temperature, and the level of this closing temperature has a significant impact on the temperature load. As the temperature rises, the arch elongates and displaces upstream. The directions of the resulting bending moment and shear force are the same as those caused by the reservoir water level, but the axial force acts in the opposite direction. Therefore, under normal circumstances, a temperature drop is detrimental to the stresses in the dam body, while a temperature rise is detrimental to the stability of the dam abutments.