Question

Autumn 2018-Pre Assessment Tash Due Date: Monday 26th March A rectangular prestressed concrete beam is to span 10 m simply supported with a of different magnitude over each half span, 20 kN/m on the left half and 60 kN/m on the right half. The span and loads are shown on the skctch below. The UDLs (which include selEweight) are to be used for load-balancing. The proposed elevation is also shown below - note that the maximum eccentricity from the centroidal axis of the beam to the line of any proposed tendon profile is 521 mm. a) To load-balance the given applied UDLs, sketch the appropriate tendon profile on this question shoet (reasonably accuratcly please), showing where along the beam length is/are the position(s) of the maximum allowable tendon eccentricity, 521 mm? descriptions of your proposed profile, such as the position(s) along the length of the maximum eccentricity of your profile. Please give qualitative and quantitative b) Are there any kinks in the profile within the span? If so, then why? If not, then why no? c) If you use the maximum eccentricity available, 521 mm, then what is the value of the effective prestress force, P, required to load-balance the given applied UDLs with your proposed profile? Rounded to a whole number, please -no decimal places. d) Where is/aro the position(s) along the tendon profile where the profile's tangent is horizontal? e) For your proposed profile and value of P, what is the eccentricity at mid-span, B? ) For the tendon profile you just decided upon to load-balance the given loads, what is/are the value(s) of the sag(s), h, of any parabolic arc(s) that you may have decided are required for the tendon profile in span ABC. If your profile has no parabolic arcs then please expand on your response to part a) as to why you decided on this. Remember, sag is measured from the chordline E) What are the angles to the horizontal, OA and Oc, of the tendon profle at the anchorages A and C? b) What are the angles to the horizontal, Os and Os , of the tangent of the tendon profile just either side of the midspan B? Angles are in radians, please. C. 52 -52 C. Over/...4)

Answer 1

Solutuem Support ertacthonst 5끼 5.63m 431.5 ち15-62 kw force no to be r at at pon caiote is located at 5.63 m Pron te Sapport 4 At 지,L 5-63, lhaa 515.62 kN-m The cabl pogde arabslic oit M Ben dong wonnent 아 515.62 -m Phe cate projleunk (parabula) te benduiz bandunig womeut, tue brojile hau to pi 」-The etee tuve pres p- tress torce = 51 5.62 X1000 mm 521 At mid-spen , B, thu eecentriclg 515 5252D m ggo