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目的:基于常用的数值模拟软件FLAC~(3D)进行二次开发,弥补现有数值模拟方法的缺陷,提出一种准确有效的隧道/巷道拱架支护数值模拟方法。创新点:1.引入抗弯和抗压能力的相关性,改进梁单元压弯极限判据;2.通过FISH语言编程,实现梁单元修正和拱架精确模拟。方法:1.通过对FLAC~(3D)中梁单元支撑理论的分析,明确其存在的缺陷,并利用算例进行证实(图4~6);2.基于传统强度理论,对梁单元现有压弯极限判据进行改进(图7和8);3.通过FISH语言编程,实现梁单元修正模型嵌入(图9);4.通过算例分析,对新模拟方法的效果进行验证(图10和13)。结论:1.改进了梁单元压弯极限判据,通过FISH语言编程实现了梁单元的修正及拱架屈服失效的模拟。2.构件压弯试验和巷道拱架支护实例分析表明:修正模型体现了在压弯组合荷载作用下梁单元屈服时弯矩和轴力的相关性;实现程序是有效的且灵敏度较高;提出的新模拟方法使计算偏差得到有效压制,拱架模型呈现出的力学行为及围岩支护作用更加接近实际,计算精度和设计可靠度更高。
OBJECTIVE: Based on the commonly used numerical simulation software FLAC 3D, to make up for the shortcomings of the existing numerical simulation methods, an accurate and effective numerical simulation method for tunnel / tunnel arch support is proposed. Innovations: 1. Introduce the correlation between bending resistance and compressive strength, and improve the ultimate bending moment limit criterion of beam elements. 2. Correct the beam elements and accurately simulate the arch by FISH language programming. Methods: 1.According to the element supporting theory of FLAC 3D beams, the existing defects were identified and verified by examples (Fig. 4 to Fig. 6). Based on the traditional strength theory, (Figure 7 and 8); 3. FISH language programming to achieve beam element correction model embedding (Figure 9); 4. Through the example analysis, the new simulation method to verify the effectiveness of (Figure 10 And 13). Conclusion: 1. The bending limit criterion of beam elements is improved. The correction of beam elements and the simulation of yield failure of arch frame are realized by FISH language programming. The analysis of component bending test and the example of tunnel arch support show that the correction model shows the correlation between bending moment and axial force of beam element yielding under the bending-bending combined load; the procedure is effective and the sensitivity is high; The proposed new simulation method can effectively suppress the calculation error, and the mechanical behavior and the supporting effect of surrounding rock in the arch model are more realistic. The calculation precision and design reliability are higher.