Advances in Civil Engineering

Research Article

Emergency Trench Shoring and Rescue: A Simplified Method for Calculating Lateral Earth Pressures

Table 3

Maximum total thrust earth-pressure distribution for braced excavation per strut. Bold values denote a failure condition where the expected resistance is less than the calculated earth-pressure force.


Trench depth	Bulk unit weight		Maximum total trust pressure				Maximum force per strut				Resistance per strut
	Bulk unit weight		Peck [6]		Tschebotarioff [9]		Peck [6]		Tschebotarioff [9]		T-L method		C-80 method		C-60 method		Equation (2)¹
	pcf	kN/m³	psf	kPa	psf	kPa	kip	kN	kip	kN	kips	kN	kips	kN	kips	kN	kips	kN

4 ft (1.2 m)	120	18.9	152.9	7.2	120.0	5.7	2.4	10.4	1.9	8.1	3.3	14.7	6.3	27.9	5.0	22.2	2.1	9.5
	125	19.6	107.3	5.1	125.0	5.9	1.7	7.3	2.0	8.5	3.3	14.7	6.3	27.9	5.0	22.2	2.1	9.5
	130	20.4	74.4	3.5	130.0	6.1	1.2	5.0	2.1	8.8	3.3	14.7	6.3	27.9	5.0	22.2	2.1	9.5
8 ft (2.4 m)	120	18.9	305.8	14.4	240.0	11.3	4.9	20.7	3.8	16.3	6.1	26.9	11.4	50.7	8.8	39.3	4.3	19.0
	125	19.6	214.5	10.1	250.0	11.8	3.4	14.6	4.0	17.0	6.1	26.9	11.4	50.7	8.8	39.3	4.3	19.0
	130	20.4	148.7	7.0	260.0	12.3	2.4	10.1	4.2	17.6	6.1	26.9	11.4	50.7	8.8	39.3	4.3	19.0
12 ft (3.7 m)	120	18.9	458.6	22.2	360.0	17.4	7.3	32.0	5.8	25.1	9.4	41.6	16.5	73.4	12.7	56.4	6.4	28.5
	125	19.6	321.8	15.6	375.0	18.2	5.1	22.4	6.0	26.2	9.4	41.6	16.5	73.4	12.7	56.4	6.4	28.5
	130	20.4	223.1	10.8	390.0	18.9	3.6	15.6	6.2	27.2	9.4	41.6	16.5	73.4	12.7	56.4	6.4	28.5
16 ft (4.9 m)	120	18.9	611.5	29.4	480.0	23.1	9.8	42.4	7.7	33.3	12.1	53.8	21.6	96.2	16.5	73.4	8.5	38.0
	125	19.6	429.0	20.6	500.0	24.1	6.9	29.7	8.0	34.6	12.1	53.8	21.6	96.2	16.5	73.4	8.5	38.0
	130	20.4	297.4	14.3	520.0	25.0	4.8	20.6	8.3	36.0	12.1	53.8	21.6	96.2	16.5	73.4	8.5	38.0
20 ft (6.1 m)	120	18.9	764.4	36.6	600.0	28.7	12.2	52.7	9.6	41.4	15.4	68.5	26.8	119.0	20.4	90.5	10.7	47.4
	125	19.6	536.3	25.7	625.0	29.9	8.6	37.0	10.0	43.1	15.4	68.5	26.8	119.0	20.4	90.5	10.7	47.4
	130	20.4	371.8	17.8	650.0	31.1	5.9	25.7	10.4	44.8	15.4	68.5	26.8	119.0	20.4	90.5	10.7	47.4

¹Bold values denote a failure condition based on either Peck [6] or Tschebotarioff [9] thrust forces.