1 Introduction 001
1.1 Research background 002
1.2 Research status of PBA method 004
1.3 Research significance 009
2 State of the art 011
2.1 Cut and cover method 011
2.2 Cover-cut method 013
2.3 New Austrian tunneling method 015
2.4 Shield method 019
2.5 Both sides heading method 020
2.6 Center drift method 022
2.7 NTR method 023
3 Introduction to PBA construction method 026
3.1 Pile-beam-arch(PBA) method 026
3.1.1 Principle of PBA method 026
3.1.2 Characteristics of the PBA method 027
3.1.3 Construction steps of the PBA method 028
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