碾压混凝土拱坝单向间隔诱导缝等效强度研究

通过对混凝土试件断裂韧度的分析，得到了碾压混凝土断裂韧度的尺寸效应规律，将该规律运用到单向间隔诱导缝等效强度计算公式中，得到与缝长有关的强度计算公式，并得出相同面积折减率下单向间隔诱导缝等效强度随缝长的增加而减小的结论。由诱导缝断面强度剩余率曲线又得到诱导缝断面强度剩余率随缝长的增加而减小，随强度等级降低而增大的结论。据此提出了碾压混凝土拱坝中诱导缝应选择相对较长的尺寸，坝体选用的混凝土强度等级在对坝体温度应力影响较小的情况下应适当提高的建议。

Equivalent strength of unidirectional interval induced joints in RCC dams

The law of size effect for RCC fracture toughness was studied experimentally and this effect was introduced into the formula for calculating the equivalent strength of unidirectional interval induced joints in dams, which is related to the length of joints. It is found that the equivalent strength of unidirectional interval induced joint decreases with the increase of its length and increases with the reduction of strength grade under the condition of the same area reduction rate. It is also found that reduction rate of strength of the induced joints section decreases with the increase of strength grade of RCC and length of induced joint according to the curve of reduction rate of the induced joint section's strength. It is suggested that the length of induced joints should be relative long and the concrete intensity should be selected to be high grade when it is permitted.