基于流变效应锚杆柔性支护在基坑中的应用

针对基坑工程预应力锚杆柔性支护的工程特点,依据流变力学理论,提出了一种新的粘弹塑性流变模型,建立了最小锚固锁定荷载的计算式.该模型体现了锚固体和基坑土体的流变效应以及面层、锚杆与基坑壁面的连接特性,并与有限差分程序FLAC3D结合,对锚杆、浆体的受力、安全系数和位移进行了数值计算.根据计算结果和现场监测,得出了预应力锚杆的最小锁定荷载、预应力锚杆筋材应力的不均匀分布和最大轴力位置、浆体剪应力的驼峰分布和面层的剪应变率及加固后坑体位移的分布等有用结论,其结果与现场监测基本吻合,数值计算能较好地反映实际情况,为有效的基坑支护提供了理论依据.

Application of flexible reinforcement with anchor in foundation pit based on rheological

A imed at the characterist ics of f lexible support of fo undat ion pit w ith prest ressed anchor for civil eng ineer ing , r heolog ical mechanics w as applied to calculate the designed parameter s and to evaluate reinfo rcement effect s. A new viso-elasto-plast ic rheological model was estabished w ith the lo cked loading formula, w hich too k on the proper ties o f bonding so il, the surro unding soil, the bolt s and the ex cav at ion surface and so o n. T he f inite dif ference method ( FA LC3D ) w as applied in the numerical calculat ion of the anchor , the g rount lo ading , the shear str ain rate, the safety factor and the displacement . Based on the calculated resul ts and the on-spot testing, plenty o f key par ameters o n the whole bonged and the prest ressed bolt w ere studied. Finally, the conclusions about the minimum locked loading , the st ress and the max imal axial dist ribut ion o f the prest ressed steal, the hump dist ribution o f shear st ress on the grount and the displacement of the reinforced fo undat ion pit and so on w ere draw n. T he numerical calculat ion w hich agrees w ith the test ing factors, can provide theoret ical basis for ef fective surrpo rt eng ineering s.