**4.3 Model test and discussion**

The test data are input in **Table 8** into the model, in turn, to obtain the support design scheme for the test set, as shown in **Table 9**.

As seen in **Table 9**, the scheme proposed by the system anchor design model for the Baishan Hydropower Station is consistent with the scheme used in actual engineering. The proposed scheme for the Ertan Hydropower Station is anchor diameter Φ30, and the anchor spacing and row spacing are @1.5 1.5. The proposed scheme for the Huangjinping Hydropower Station is anchor diameter Φ32, and the anchor spacing and row spacing are @1.2 1.2. The proposed schemes are safer and more reliable than the scheme used in actual engineering.


#### **Table 9.**

*Comparison between the actual scheme and the proposed scheme of the intelligent design model.*

The schemes suggested by the intelligent design model are evaluated using the concept of support strength criteria presented in Section 3.3. The comparison of the proposed schemes from the intelligent design model and the actual support schemes are shown in **Figure 14**.

In high in situ stress areas, the engineering analogy method has fewer projects to provide a reliable reference for support schemes with different plant spans and strength-stress ratios. Therefore, in actual engineering, there may be a situation where the design support strength is low, such as Dagangshan Hydropower Station in Figure 15, which may cause dangerous situations during construction. In low and medium in situ stress areas, the same low strength of system anchor support was observed in Mengdigou, Baise, and Nuozhadu hydropower stations designed by the traditional method. This indicates that the engineering analogy method has difficulty

#### **Figure 14.**

*Comparison of the support strength index of the actual scheme and the scheme proposed by the intelligent design model.*

*Support Strength Criteria and Intelligent Design of Underground Powerhouses DOI: http://dx.doi.org/10.5772/intechopen.102791*

selecting an appropriate system anchor support scheme in situations such as high in situ stress and uncommon plant spans and that the design reliability is low. However, the support strengths suggested by the intelligent design model are generally better than those used in the actual project, and generally, the support index is above 1.0. In relatively complex areas of high in situ stress, such as the Houziyan and Dagangshan hydropower stations, intelligent design models provide safer design schemes than actual engineering. This shows that the intelligent design model can provide a more reliable and economical support scheme than the traditional engineering analogy method and can be used as a reference for the design of system anchors for underground plants in practical engineering.
