DAMAGE TO BRIDGES DURING EARTHQUAKES 643 



from bank to bank. The narrowing of the distance between banks 

 which is thus indicated is considerable. This is shown in Fig. 3, 

 B and C. 



EARTHQUAKE OF SCHONAI, JAPAN, IN 1 894 



An interesting illustration of the approach of the abutments of a 

 rustic bridge during the Schonai earthquake is seen in Fig. 4, B. In 

 this case the girder has slid up over one of the abutments so as to 

 allow the latter to move toward the stream. ' 



GREAT ASSAM EARTHQUAKE OF JUNE 12, 1897^ 



Next to the Mino-Owari earthquake this great disturbance has 

 furnished perhaps the largest number of examples of wrecked bridges. 

 These will be discussed, therefore, m some detail: 



Bridge on Grand Trunk Railroad west of Gauhati : 



At the western end of the Gauhati Bazar is a bridge of three girders carrying 

 the Grand Trunk Road over a small stream, which here joins the Brahmaputra. 

 The original length of the bridge, as measured along the hand rail, was 99 feet, 

 4 inches, v/hile the present length, between the same points, is 97 feet, 10 inches. 

 The bridge has therefore been shortened 18 inches. This has been caused by 

 fissuring of the banks on both sides of the stream, the abutments having been 

 carried forv/ard. One of the piers has been tilted over probably by the thrust of 

 the girder. There are no cracks in the abutments. (P. 266.) 



Assam Bengal Railway (Reported by T. D. Latouche) : 



I v/ent out along this line as far as the bridge over the Kapili River about 

 forty-one miles from Gauhati. The rock cuttings, in gneiss, have not been affected 

 in the slightest degree by the shock, but v/here the line passes over alluvium, the 

 embankment has settled dov/n, carrying the rails v/ith it. Many of the culverts 

 are badly cracked, apparently from the same cause as has affected the bridge 

 mentioned above at Gauhati, viz., the fissuring of the banks of the streams and 

 the consequent sliding forv/ard of the abutments and v/ing v/alls. The piers of 

 the large bridge over the Kapili are cracked through horizontally at about 2 feet 

 above the ground level, and the girders have shifted lengthwise on top of the 

 piers. (P. 267.) 



Bridge over the Bara Khal (Reported by G. E. Grimes) : 



In the case of the bridge over the Bara Khal the piers have fallen right over 

 into the river and disappeared entirely; before the earthquake this bridge had 



' D. Kikuchi, Recent Seismological Investigations in Japan, Pub. E. I. C-, No. 19 

 (Tokyo), Tyo4, Fig. 46. 



"R.B.Oldhsim, Mem. Geol.Surv. India, Vol XXIX, (iSgg). 



