In order to enhance the service hfe of hollow steel for rock drill stem, the odd number side section shape hollow steel has been designed.

为了提高凿岩钎杆用中空钢的使用寿命，设计了奇数边截面形状的中空钢。

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The achievements in this paper may be referenced for the fire protection design of practical engineering with concrete filled steel rectangular hollow section columns.

本文的研究成果可为有关矩形钢管混凝土工程进行抗火设计时提供参考。

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The practice proved that strengthen prestressed hollow by method of section-steel bonded, safe and reliable, low investment, fast and interference small, the effect was very good.

工程实践证明，运用粘型钢技术加固预应力空心板，安全可靠，速度快，干扰小，效果好。

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