中文摘要：

为研究高庙子钠基膨润土GMZ001的三向膨胀力特性,改进了三向胀缩仪,扩大了该仪器膨胀力的测量范围,进行了一系列不同干密度和不同初始吸力的三向膨胀力试验。研究结果表明：①在所研究的干密度、含水率范围内,竖向（平行于压实方向）膨胀力、水平（垂直于压实方向）膨胀力均主要与干密度有关,初始吸力对其没有明显影响。②水平膨胀力与竖向膨胀力之比随干密度的增大而减小;当干密度较小时,竖向膨胀力与水平膨胀力基本相等;当干密度大于1.6 g/cm3时,水平膨胀力与竖向膨胀力之比变化很小,其值稳定在0.78左右。③初始吸力、干密度均会显著影响膨胀力随时间变化曲线的形状;对于高吸力高干密度试样,其膨胀力–时间关系曲线在中间一段出现＂平台＂。④相同初始吸力下,膨胀力变化速率随干密度的增大有所增加,但不同干密度试样的膨胀力变化速率的差异随时间逐渐缩小;相同干密度下,尽管初始阶段高吸力试样的膨胀力发展更快,但一段时间后低吸力试样的膨胀力变化速率会比高吸力试样的大。⑤膨胀力最终平衡时间随干密度增大有所增加,而初始吸力对平衡时间影响不大。

英文摘要：

An experimental research on characteristics of 3D swelling pressure of GMZ001 bentonite is reported. Samples are prepared using the static uniaxial compaction. Tests are preformed by use of 3D swelling-shrinkage apparatus, of which some modification has been made to enlarge the measuring range of swelling pressure. For the specimens investigated in this study, both the vertical （paraUel to the direction of compaction） and horizontal （perpendicular to the direction of compaction） swelling pressures show exponential functions against their dry density, however, the swelling pressures are independent of the initial suction of samples. The increase of the dry density results in the decrease of the ratio of horizontal and vertical swelling pressures. When the dry density is lower than 1.45 g/cm3, the vertical and horizontal swelling pressures are almost identical, while an invariable ratio of horizontal and vertical swelling pressures of 0.78 is obtained when the dry density is larger than 1.6 g/cm3. Evolution of the swelling pressure is affected by both the dry density and the initial suction of the specimens. For specimens with higher dry density and higher initial suction, the development of swelling pressure ceases for a while in the course of hydration before it reaches its final maximum. The increase of the dry density leads to the increase of the development speed of swelling pressure, however, the speed difference between the higher and lower dry density specimens becomes insignificant with time. Compared with the higher suction specimens, the development rate of swelling pressure of specimens with the lower suction is inferior at early stage, but it becomes superior after a period of time. The equilibrium time of the maximum swelling pressure relates to the dry density, while the initial suction does not play an important role in it.