加高扩容贮灰场地震响应特性及其稳定性评价

贮灰场主要用于储存燃煤电厂排出的粉煤灰和炉渣,在加高扩容时应特别注意地震作用下的稳定性。通过现场试验和数值模拟手段,研究了某贮灰场加高扩容前后的液化可能性、动力响应及稳定性。结果表明:(a)加高扩容后四级坝的峰值加速度和峰值水平位移相比现状三级坝响应更加显著。(b)子坝坝体粉煤灰不液化,库内可能出现液化。输入地震动峰值加速度越高,库内液化区明显增大,加高扩容后库内液化区域增大。(c)地震作用下贮灰场三级坝与拟筑四级坝的潜在滑动面位置均位于子坝坝系。随拟筑四级坝高程增加,最小安全系数减小。根据该贮灰场Ⅷ度抗震设防烈度要求,加高扩容前后贮灰场的稳定性均满足抗震规范要求。研究成果可为贮灰场加高扩容后的抗震设计提供理论依据。

Seismic response characteristics and stability evaluation of heightened and expanded ash storage field

Ash storage field is mainly used to store fly ash and slag discharged from coal-fired power plants. When increasing capacity, special attention should be paid to the stability under seismic action. The liquefaction possibility, dynamic response and stability of a fly ash storage field before and after after heightening and expanding were studied by field test and numerical simulation. The results show that: 1)the peak acceleration and peak horizontal displacement of the four-stage dam are more significant than that of the three-stage dam. 2)the fly ash of the dam body does not liquefy and may liquefy in the reservoir. The higher the peak acceleration of input ground motion, the larger the liquefied area in the reservoir. 3)the potential sliding surfaces of the three-stage dam and the four-stage dam are located in the sub-dam system. The minimum factor of safety decreases with the increase of the proposed dam height. According to the requirement of VIII degree seismic fortification intensity of the ash field, the stability of the ash field before and after increasing the capacity can meet the requirements of the seismic code. The research results can provide a theoretical basis for the seismic design of ash storage field after heightening and expanding.