固化淤泥重塑土力学性质及其强度来源

Mechanical characteristics and strength source of remolded solidified dredged material

对不同水泥掺加量的固化淤泥及其重塑土进行了无侧限抗压强度试验和直接剪切试验,并对固化土和重塑土的应力-应变关系曲线、无侧限抗压强度、黏聚力和内摩擦角进行了比较分析。结果表明:随着水泥量和龄期的增加,固化淤泥的脆性增强,塑性减弱;重塑土的应力-应变关系受水泥量和龄期的影响不大,随着应变的增加,应力增长缓慢,塑性变形非常大。固化土的无侧限抗压强度、黏聚力均随着水泥量和龄期的增加而增大,而内摩擦角则有减小的趋势。重塑土相对于原状土无侧限抗压强度和黏聚力都有较大程度的折减,并且水泥量和龄期越大,折减越多;内摩擦角随着水泥量和龄期的增加有小幅度提高。重塑土强度主要来源于破碎固化土团间的摩擦和咬合作用,因此,在固化淤泥重塑土的实际工程应用中,初始固化土的处理强度不应太高。

Unconfined compressive strength tests and direct shear tests were conducted to cement solidified dredged material （SDM） and remolded solidified dredged material（RSDM）. The stress-strain curves and unconfined compressive strength and cohesion and internal friction angle of SDM and RSDM were compared and analyzed. Test results show that the brittleness of SDM increase but the plasticity deduce. However, the cement content and curing time do little effect on RSDM, the stress grows slowly while the strain increase, the plastic deformation is great. The unconfined compressive strength and cohesion of SDM gains with cement content or solidified curing time increases, however the internal friction angle knock down. The unconfined compressive strength and cohesion of RSDM reduce a little comparing to SDM, the more the cement content and curing time longer the reduction is larger. The internal friction angle of RSDM increase as the cement content and curing time become gains. The unconfined compressive strength of RSDM largely comes from friction effect among the crushed solidified soil mass.