An Analytical Solution for Stress and Displacement Field for Arbitrarily Positioned Twin-Tunnel Excavation at Great Depth

Table 4

Circumferential stress owing to the transverse tension of unit force.

Distance	2.1		2.2		2.4
(°)	84.4	180	84.4	0	84.6	0
Haddon’s	2.607	-0.970	2.611	-0.918	2.619	-0.905
Proposed	2.461	-1.814	2.499	-0.933	2.538	-0.869
Error(%)	5.60	87.1	4.29	1.63	3.09	3.98
Distance	2.6		3		4
(°)	84.8	0.0	85.4	0.0	86.8	0.0
Haddon’s	2.628	-0.899	2.650	-0.896	2.715	-0.908
Proposed	2.559	-0.847	2.594	-0.843	2.689	-0.875
Error(%)	2.63	5.78	2.11	5.92	0.96	3.63