By analyzing the engineering instances,safe and smooth construction technology of thick liquefied soil layer of main well collar set of Yangying Coal Mine is summarized systematically in this paper,and this provides technical reference for future excavation and masonry of shaft after passing through liquefied or quicksand sections.

The paper introduces the theoretic basis of application of ramming expanded pile in practical project and the design process,highlighting the cause why the ramming expanded pile is difficult to drive into liquid soil layer and the technical measures that should be taken in its design and construction.

The rising of ground water table caused by the coming sea level rise in the region of Shanghai will intensify soil liquefaction.

Based on the API code, the double-parameter modified method and the revised computational formula for lateral dynamic p–y curves of pile foundation in liquefiable soil layers are presented by using pile-soil shaking table tests, and as a result, the unacceptable problem of the current coefficients for calculating the dynamic p-y curves by the API code in engineering practice can be solved.

In order to ascertain a reasonable strip mining project for the coal mining under villages with thin bedrocks under the thick alluvium in Linhuan, the characters of surface subsidence in strip mining were studied by numerical simulation method based on discrete element.

Simulating test on damage regularities of thick sandy soil layer and load distribution on key roof block in shallow coal seams;

Studies on load-transmitting factor of thick sandy soil layer on key roof stratum in shallow seam mining;

Based on the measurement in site, the phenomenon of load reducing on roof key blocks structure under thick sandy soil layer was discovered.