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为了给软土堆载工程监测提供依据,讨论了工程中常采用的沉降速率10mm·d-1、水平位移速率5mm·d-1作为各类软土地基稳定性控制指标的适用性,并研究了不同加载速率和地基处理方式对软土地基变形的影响。结合上海某工程塑料排水板地基的监测数据,研究了堆载作用下软土地基的变形速率特征,并采用有限元法详细分析了加载速率和地基处理方式(有、无塑料排水板)对软土地基变形速率的影响。研究结果表明:这种采用位移速率为控制指标的方法并不能完全准确反映地基的稳定性,在加载初期安全性较大时位移速率会超过控制标准,而在地基破坏前的位移速率却低于控制标准;加载速率对变形速率有直接影响,加载速率越大地基变形速率也越大;地基的排水性能对变形速率有显著影响,打设塑料排水板的地基比其他类型处理的地基具有更大的变形速率。此外,对于塑料排水板软土地基,软土的固结压密以及排水系统性能的弱化也会造成该类地基的变形速率呈现前期快而后期慢的反常现象。因此,对于塑料排水板软土地基的稳定性控制,这种特殊现象在地基变形监测数据分析中应该予以重视。
In order to provide the basis for the monitoring of soft soil loading, the applicability of settlement rate of 10 mm · d-1 and horizontal displacement rate of 5 mm · d-1, which are commonly used in engineering, are discussed as the control indexes for the stability of various types of soft ground. Influence of Different Loading Rate and Foundation Treatment on Deformation of Soft Soil Foundation. Combined with the monitoring data of a plastic drainage board foundation in Shanghai, the deformation rate characteristics of soft soil foundation under surcharge loading are studied. The effects of loading rate and foundation treatment (with and without plastic drainage board) on the soft Influence of soil foundation deformation rate. The results show that the method using displacement rate as control index can not accurately reflect the stability of foundation. When the safety is large during initial loading, the displacement rate will exceed the control standard, but the displacement rate before foundation destruction is lower than Control rate; the loading rate has a direct impact on the deformation rate, the greater the loading rate, the greater the deformation rate of the foundation; the drainage performance of the foundation has a significant impact on the deformation rate, laying plastic drainage board foundation than other types of treatment has a greater foundation The rate of deformation. In addition, for plastic drainage soft soil foundation, soft soil consolidation compaction and drainage system performance weakening will also cause the deformation rate of such foundation showed early and late slow anomaly. Therefore, for the stability control of soft soil foundation of plastic drainage board, this special phenomenon should be paid more attention in the analysis of deformation data of foundation.