南海珊瑚泥是珊瑚群体死后的骨胳、碎屑聚积形成的海洋岩土体钙质软泥，具有特殊的工程性状，研究其在荷载作用下与时间相关的长期非线性变形对吹填岛礁建设和长期稳定分析具有重要意义。对珊瑚泥进行了3组不同加卸载方案的一维固结压缩试验，通过改变加载时间与加卸载循环圈数探究应力历史对其长期变形性质的影响，并针对珊瑚泥在加卸载试验条件下呈现出的瞬时变形、延时衰减与延时稳定变形3阶段规律，采用改进的Burgers模型拟合不同竖向应力作用下的ε-t（应变−时间）曲线，具有较高拟合精度。同时分析模型参数后发现，随着分级加载时间提高，瞬时应变增量及其增长率下降，最终荷载下的延时衰减时间缩短，延时稳定应变速率及最终荷载下的总应变增量减小。同一加卸载循环圈数中，同竖向应力下卸载阶段的瞬时应变增量小于加载阶段。随着加卸载循环圈数的增加，加、卸载各阶段瞬时应变增量均减小且二者相近，延时衰减时间缩短，延时稳定应变速率及最终荷载下的总应变增量减小。研究了分级加载时间与加卸载循环圈数对珊瑚泥长期变形性质的影响，旨在为岛礁建设中的堆载预压方案提供理论依据。南海珊瑚泥

South China Sea coral mud is a calcareous ooze of marine rock and soilformed by the accumulation of bones and debris after the death of coral groups

which has special engineering properties. It is significant to investigate itstime dependent long-term nonlinear deformation under load for the constructionand long-term stability analysis of dredger fill islands and reefs. Threegroups of one-dimensional consolidation compression tests of coral mud withdifferent loading and unloading schemes were carried out

and the influence ofstress history on its long-term deformation properties was explored by changingthe loading time and loading-unloading loops. According to the three-stage lawof coral mud’s instantaneous deformation

delayed attenuation deformation anddelayed stable deformation under loading and unloading test conditions

theimproved Burgers model was used to fit ε-t curves under different vertical stresses

which has high fittingaccuracy. Meanwhile

after analyzing the model parameters

it was found that theinstantaneous strain increment and its growth rate decrease with the increaseof graded loading time

the duration of delayed attenuation under the finalload decreases

and the delayed stable strain rate and the total strain incrementunder the final load decrease. In the same loading-unloadingloops

the instantaneous strain increment in the unloading stage is smallerthan that in the loading stage under the same vertical stresses. With theincrease of loading-unloading loops

the instantaneous strain increment in eachstage of loading and unloading decreases and is close to each other

theduration of delayed attenuation deformation

the delayed stable strain rate andtotal strain increment under the final load decrease. The effects of gradedloading time and loading and unloading cycles on the long-term deformationproperties of coral mud were studied to provide theoretical basis for surchargepreloading scheme in island reef construction.