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281.

In case the resultant of all the forces acting on a dam passes outside the base, the dam would overturn unless

A.	It can resist tensile stress	B.	Additional weight is provided on the body of the dam
C.	Friction pads are provided	D.	Anchor blocks are provided
E.	Coefficient of driction of the material is increased

282.

The stress in the dam should be within the specified limits for the body of dam in the foundations. If the stress at the toe and heel are excessive, they can be brought within permissible limits by

A.	Grouting	B.	Providing anchor blocks
C.	Providing friction blocks	D.	Providing filters
E.	Any of the above

283.

By the usual gravity analysis as per B.I.S., the permissible tensile stresses at the upstream face of the dam under earthquake loading, should not exceed

A.	50 kg/ cm2	B.	100 kg/ cm2
C.	150 kg/ cm2	D.	200 kg/ cm2
E.	Zero

284.

Which assumption is not valid in the analysis of gravity dams

A.	The material in the foundation and in the body of the dam is isotropic and homogeneous	B.	The foundation and the dam behave as one unit, the joint being a perfect one
C.	No loads are transferred to abutments by beam action	D.	The stress in the foundation and the body of the dam are within plastic limits
E.	No movements are caused in the foundations due to transference of the load

285.

Essentially the gravity dam resists the loads to which it is exposed, due to its

A.	Size	B.	Volume
C.	Mass	D.	High tensile stress
E.	Gravity

286.

In a Buttress dam the inclination of the deck with horizontal is kept between

A.	10? to 15?	B.	15? to 20?
C.	25? to 30?	D.	35? to 40?
E.	60? to 75?

287.

In case of Buttress dams, too steep slopes

A.	Increase the tendency to sliding	B.	Increase inclined stress at heel
C.	Increase tendency to over turning	D.	Increase stresses at heels only
E.	Increase tensile stress on upstream side of dam

288.

In Buttress dam, too flat a slope causes

A.	Excessive tensile stress on upstream face	B.	A very high inclined stress at the heel
C.	Overloading of buttress sections	D.	Increased tendency to overturning
E.	Excessive tensile stresses in the foundation and the body of the dam

289.

Which one of the following is not usually considered particular advantage of a Buttress dam?

A.	Economy in use of concrete	B.	Less uplift force
C.	The power house and switchyard etc. can be located between the buttresses	D.	Because of thin members, the volume changes are significant
E.	Due to thin section, the problem of temperature control is minimised.

290.

Which one of the following is not a disadvantage due to a Buttress dam?

A.	The structure being self-sealing, it is not sensitive to accidental rise in water level above the designed full supply level	B.	Bearing stress of the foundtions are higher
C.	Problems arising out of large number of joints in the dam	D.	Significance of volume changes of thin members
E.	Overflow arrangements