结构性土体固结压力的力学效应

针对黄土、盐渍土、红土、下蜀土、软土以及添加水泥和石灰固化后的吹填土等特殊土体表现为结构强度高、先期固结压力大，且地表土超固结比十分高，存在随着土层深度的增加，前期固结压力值减小的反常规现象，开展了土体结构力、结构强度和结构性土体等一系列问题的研究。通过对大量试验资料的分析，讨论了影响土体前期固结压力的主要影响因素，包括土体胶结类型、成因特点、原岩结构以及环境等因素；根据原状土和重塑土的圧缩曲线半定量地确定结构强度值；并探讨了结构力的形成机制。研究结果表明:土体结构强度受到影响则导致土体前期固结压力发生改变；前期固结压力实质上是由传统定义上的前期固结压力与结构强度两部分构成；结构力即为颗粒之间形成的固化胶结连结力。最后给出了结构强度和结构性土的定义。 

Mechanical Effect of Pre-consolidation Pressure of Structural Behavior Soil

Special soil such as loess, saline soil, red soil, Xiashu loess, soft soil, or solidified dredger fill, has high pre-consolidation pressure (Pc) and high over-consolidation ratio (OCR), and with the increase of soil depth, the Pc value decreases obviously. To investigate these uncommon facts, soil structure force, structural strength and other issues in structural soils were analyzed. From experimental data, the factors affecting pre-consolidation pressure (Pc) were discussed, including the soil cementation type, soil genesis characteristics, original rock structure and environment. Soil structural strength was determined according to the compression curves of undisturbed and remolded soil, and the formation mechanism of structure force was explored. The results show that those factors affect the soil structure strength, which changes pre-consolidation pressure. It is found that the pre-consolidation pressure includes two parts, the traditional pre-consolidation pressure and soil structural strength; the structure force is the solidified bond strength between particles. Finally, the definitions of structural strength and structural soil were presented.