一、引言土石坝防渗体的开裂,对于其结构安全来说,被认为是一个严重的威胁。不过,它只在最近大约20年才得到重视,在几个高坝中曾观察到严重的开裂,这几个坝是用重型机械仔细控制压实施工的。由于大容量的近代运输机械的发展,施工速度较快,因之,对施工末期坝体内部的孔隙压力分布、沉降和应力的重分布有较大影响。坝的防渗墙的开裂是由于张应力产生的,张应力的产生则是在狭窄的土区内位移差的结果。产生开裂的机理的多样性已为一些研究者所描述。开裂的某些形式已在一些工程中观察到,而更多的则是基于间接证明所支持的思索所作的设想。 I. INTRODUCTION Cracking of earth-rock dam seepage control body is regarded as a serious threat to its structural safety. However, it has only been valued recently for about 20 years and severe cracking has been observed in several high dams, which are carefully controlled with heavy machinery for compaction. Due to the development of large-capacity modern transportation machinery, the construction speed is relatively high. Therefore, the pore pressure distribution, settlement and stress redistribution inside the dam at the end of construction are greatly affected. The cracking of the cut-off wall of the dam is due to tensile stress, and the generation of tensile stress is the result of the poor displacement in a narrow area. The variety of mechanisms responsible for cracking has been described by some researchers. Some forms of cracking have been observed in some projects, and more often based on the assumptions made by the evidence supported by indirect proof.