102 NOTES ON DOCKS AND DOCK CONSTRUCTION. 



advocates stock ramming as a means of stopping leaks under 

 permanent structures, or securing or underpinning the founda- 

 tions of works, which, placed on clay or clayey strata, show 

 signs of settlement. 



To carry out this operation, holes 3 inches to 6 inches in 

 diameter are bored at inter\ 7 als of from 5 to 10 feet, according 

 to circumstances, to the bottom of the work; into these holes 

 pipes are placed extending some inches into the strata beneath 

 (Figs. 65, 66). 



Clay worked up with cement or hydraulic lime, sand mixed 

 with iron filings and sal ammoniac, partly set Portland cement, 



Quay Wall 



Dock Entrance. 



FIG. 65. 



FIG. GG. 



or fine Portland and Medina cement concrete is then made up 

 into convenient sizes to handle, and rammed down through the 

 pipes by a heavy ram, worked by a hand or steam ringing-engine, 

 so as to force the material under the foundation and into the 

 soft strata below. 1 



Stopping Joints. Before grouting under water, Mr. W. R. 

 Kinipple, M.I.C.E., 2 adopts the following methods of stopping 

 open joints in concrete-block work. For horizontal joints be- 

 tween blocks, comparatively close canvas bagging is forced in 

 a few inches and firmly caulked, similar to caulking ordinary 

 seams of planking. 



In vertical joints, the sides are trimmed down or cut away 

 when necessary, and slightly dovetailed in order to give a 

 hold for the stopping. For the narrower openings from 2 to 

 4 inches wide, thin canvas cases, making rolls of about 6 inches 

 diameter, are used. These cases are partly filled with cement 



1 Engineering, vol. liii. p. G09. 2 Jlid., vol. liii. p. 647. 



