Field Tests on the Attenuation Characteristics of the Blast Air Waves in a Long Road Tunnel: A Case Study

Table 2

Overpressure in the tunnel induced by blasting.

Zone no.	Test no.	Δp1 (kPa)	Δp2 (kPa)	V1 (m^3)	V2 (m^3)	l (m)	L1 (m)	L2 (m)	Exponential β	Mean of β
Zone I	1-1	26.803	23.762	14972	18871	50	192	242	0.520	β1 = 0.515
	1-2	22.388	19.503	12555	16454	50	161	211	0.509
	1-3	36.814	32.094	12945	16844	50	166	216	0.521
	1-4	29.190	25.250	11697	15596	50	150	200	0.504
	1-5	25.837	22.587	13256	17156	50	170	220	0.521
Zone II	2-1	19.080	9.849	20665	27381	100	265	365	2.350	β2 = 2.66
	2-2	20.105	10.026	20899	27615	100	268	368	2.497
	2-3	16.359	7.720	21289	28005	100	273	373	2.739
	2-4	15.908	6.815	20275	26991	100	251	351	2.963
	2-5	18.670	7.921	18403	25120	100	236	336	2.756
Zone III	3-1	8.583	7.881	25254	37760	200	350	550	0.212	β3 = 0.29
	3-2	10.494	9.109	23373	35879	200	314	514	0.330
	3-3	8.259	7.350	24310	36816	200	327	527	0.281
	3-4	7.595	6.608	25126	37632	200	335	535	0.345
	3-5	9.859	8.828	26437	38943	200	363	563	0.285
Zone IV	4-1	6.456	1.561	36614	49235	150	525	675	4.793	β4 = 4.45
	4-2	5.625	1.655	36614	49235	150	525	675	4.131
	4-3	7.259	1.989	36880	49521	150	530	680	4.393
	4-4	5.936	1.289	31877	44498	150	550	700	4.583
	4-5	7.853	2.205	37067	49688	150	533	683	4.335