The article on the next page from the San Francisco Chronicle, January 27, 1996, describes very serious problems of subsidence,
water supply, and environmental pollution that exist today in Mexico City. A stratum of very soft, very high water content clay is the source of most of the settlement that accompanies the pumping of water from the underlying aquifer systems. The clay stratum thickness averaged 79 ft in 1936, and had an average water content of 356 percent. The soil solids have a specific gravity of 2.65. The average settlement of 22 feet during the 60 year period referred to in the newspaper
1 answer:
Answer:
246.3%
the complete question is found in the attached document
Step-by-step explanation:
1st step:
using 1936 data,
w1= 356% = 3.56(356/100) , H= 79 feet
specific gravity = 2.65
Sₓ= 100%= 1
initial void ratio(e₀)= (w1 x specific gravity)/Sₓ
=3.56 x 2.65/1 = 9.434
2nd step
using 1996 data
ΔH= 22ft
ΔH/H = Δe/(1 + e₀)
22/79 = Δe/(1+9.434)
0.278=Δe/10.434
Δe= 0.278 x 10.434
Δe= 2.905
Δe= e₀ - eₓ
eₓ= e₀-Δe
eₓ= 9.434 - 2.905
eₓ= 6.529
3rd step
calculating water content in 1996
eₓ =6.529, specific gravity= 2.65, Sₓ= 100%
W2 X 2.65 = 1 x 6.529
w2 = 6.529/2.65 = 2.463 = 246.3%
You might be interested in