得出如下结论：大坝的自重和坝中上高程地基减弱是造成拱坝下游面最初发生纵向裂纹的主要原因；

The results shown that: weight and weak foundation close to middle-upper dam lead the vertical cracks to propagate along the downstream wall;

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在非功能式强度型光纤传感器中，造成光强变化而导致较大信号误差的主要原因有如下几个方面：（1）光源输出光功率的变化；

For the non-function intensity type fiber optic sensors, the main intensity errors are caused by the variation of (1)source device output optical power;

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在非功能式强度型光纤传感器中，造成光强变化而导致较大信号误差的主要原因有如下几个方面：（1）光源输出光功率的变化；

For the non-function intensity type fiber optic sensors, the main intensity errors are caused by the variation of (1)source device output optical power;

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