5. Soft Foundation. 6. Wet ground.
8. Brick and Concrete Sewer, Evanston, Ill., Eng. Contracting, Vol. 46, p. 227.
Fig. 22.
| 1. Tunnel Sections. | 2. Open Cut Sections. | ||||
| Type A. | Type B. | Type C. | Type D. | ||
| Where Rock is more than 16′ above Springing Line. | Where Rock is more than 7′ and less than 16′ above Springing Line on both Sides. | Where Rock is between Springing Line and 7′ above Springing Line on both Sides. | Where Rock drops below Springing Line on either Side. | 16′ 6″ Sewer. 25′ Fill | Where Rock is above Springing Line |
| Mill Creek Sewer, St. Louis, Eng. Record, Vol. 70, pp. 434, 435. | |||||
3. Circular Concrete Section in Soft and Hard Ground, Eng. Record, Vol. 59, p. 570.
4. Semi-Elliptical Section, Louisville, Ky., Eng. News, Vol. 62, p. 416.