Evaluation of effective parameters on the seismic response of underground cavities considering near-field and far-field earthquakes

Document Type : Research Article


1 Department of civil engineering, Faculty of Engineering, Yazd University, Yazd, Iran

2 Civil Engineering Department, Faculty of Engineering, Yazd University, Yazd, Iran

3 Department of Civil Engineering, Faculty of Engineering, Ardakan University, Ardakan, Iran


The existence of underground cavities such as aqueducts and water supply pipelines cause changes in the estimated seismic response on the ground. Since the characteristics of an earthquake are different near and far from the seismogenic source and the corresponding regulations have not considered near- and far-field effects on loading, it is necessary to study such effects. This study has used the two-dimensional Plaxis software to investigate seismic responses on ground while there are underground circular cavities.To this end, a set of near- and far-field accelerograms belonging to Bam, Landers and Loma Prieta were selected. Those recordings were different in terms of frequency.To examine the effect of soil type, four types with different mechanical characteristics were selected, and the seismic responses of ground were studied in the presence and absence of a cavity. The effect of buried depth of cavity was evaluated with regard to two different buried depths. The results showed that the presence of a cavity leads to an amplified response of ground. For instance, the amplification index of the displacement on ground with and without cavities in the most critical conditions (Landres earthquake) was found to be 4.8 and 6 as recorded in near- and far-field, respectively. Moreover, the farther from the cavity center (X/R > 4), the less amplification was observed on ground under different loadings. The selected parameters also proved to have significant effects on the acceleration and displacement on surface of the ground. To gain more insight about these effects, further research is needed


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