CAJ | 학술논문

盾构施工过程中，由于盾尾建筑空隙的存在，土体会受到较大的卸荷扰动，尤其是对于结构性较强的黏土。通过卸荷拉力来模拟土体受到的卸荷扰动，进行排水剪切蠕变试验。试验结果表明：卸荷拉力越大，土体的扰动程度增大，同级荷载作用下土样的变形越大，且加载压力较小时土样的变形属于稳定型蠕变，蠕变速率随着卸荷拉力的增大而增大，加载压力较大时土样的变形属于衰减型蠕变；与Singh-Mitchell蠕变模型进行比较，发现卸荷拉力较小土样Singh-Mitchell蠕变模型的计算值与试验值相比吻合较好，但当卸荷拉力较大时，模型计算值与实验值相比有较大的误差；修正了Singh-Mitchell蠕变模型的参数，提出考虑卸荷扰动的修正Singh-Mitchell蠕变模型，计算结果与试验数据在加载压力和卸荷拉力较大时吻合较好，对工程实际有一定的指导意义。
순구시공과정중，유우순미건축공극적존재，토체회수도교대적사하우동，우기시대우결구성교강적점토。통과사하랍력래모의토체수도적사하우동，진행배수전절연변시험。시험결과표명：사하랍력월대，토체적우동정도증대，동급하재작용하토양적변형월대，차가재압력교소시토양적변형속우은정형연변，연변속솔수착사하랍력적증대이증대，가재압력교대시토양적변형속우쇠감형연변；여Singh-Mitchell연변모형진행비교，발현사하랍력교소토양Singh-Mitchell연변모형적계산치여시험치상비문합교호，단당사하랍력교대시，모형계산치여실험치상비유교대적오차；수정료Singh-Mitchell연변모형적삼수，제출고필사하우동적수정Singh-Mitchell연변모형，계산결과여시험수거재가재압력화사하랍력교대시문합교호，대공정실제유일정적지도의의。
During the shield construction,the surrounding soil would be disturbed for unloading due to shield-end structural spacing.The soil disturbance is especially for clay with strong structure.This paper is to simulate the unloading disturbance of shield soils.The drained shear creep tests are conducted.The results indicate that the deformation under the same load increases with unload increasing.The deformation is steady creep when loading stress is small.Creep rate becomes greater with unloads increasing.The deformation is attenuation creep when loading stress is large.The results are compared with Singh-Mitchell creep model.It is found that the calculated value coincides well with the test data under small loading stress.But,it has large deviation under big loading stress.Therefore we revise the parameters of Singh-Mitchell creep model.A revised Singh-Mitchell creep model considering unloading disturbance is put forward.The calculated value coincides well with the test data under big loading stress and unloading stress.