DESIGN OF VERTICAL ALIGNMET

Transcription

1 DESIN OF VERTICAL ALINMET Longtudnal gradent : max 0,5% (max see the assgnment paper) Markng of longtudnal gradent n drecton of chanage: + [%].. ascent n the drecton of chanage [%].. descent n the drecton of chanage Resultng gradent m (must be verfed at each pont of the road values of mmax for hlly terran): M S 2 category S 6,5 and S 7,5... M Mmax 8,5% category S 9,5 and S 11,5... M M max 7,5% permtted mnmum value... M Mmn 0,3% recommended mnmum value... M Mmn 0,5% DESIN OF VERTICAL ALINMENT LONITUDINAL PROFILE (1 : / 100) Process of plottng the frst phase - see fg. 0100: axs (black) vertcal and horzontal (ncludng the descrpton of the chanage every 100 m 0.1; ;...) choce of reference plane (at least 8 m below the lowest ntersected contour lne respect the scale!!!) plottng the terran lne n ponts every 10 m determne the elevaton of each pont by nterpolaton from 2

2 dmensons n fg whch are measured perpendcularly to the contour lnes: dmenson B measured to the lower contour lne dmenson C measured to the hgher contour lne example from fg. 0110: terran elevaton [m] = lower contour lne + [B / (B + C)] Fg (determnng the elevaton of a pont at the centre lne n the plan)

3 Fg (longtudnal profle frst phase of plottng) plottng vertces of elevaton polygon at frst (example n fg. 0120) accordng to the followng prncples: ponts A and B have the same elevaton as the terran lne

4 vertcal algnment desgned wthout gradent lost (example of poor desgn n fg. 0130) fll (embankment) = vertcal algnment terran 10 m cut (excavaton) = terran vertcal algnment 6 m (wthout the need of geologcal assessment) other vertces (PVI1, PVI2,...) choose reasonably (take nto account the maxmum flls and cuts to balance the earthworks) Fg (desgn of elevaton polygon and vertcal curves) Fg (poor vertcal algnment desgn wth gradent lost and wthout possblty of full dranage)

5 read coordnates of vertces PVI of elevaton polygon: PVI = [chanage (St); elevaton (H)] [St] = km (5 decmal places) [H] = m (2 decmal places) calculate longtudnal gradents between each 2 vertces and +1 (at least 2 decmal places!!!) % H St 1 1 H St 10 H 1 St H 1 St verfy between all vertces PVI and PVI+1 : 0,5% max Vertcal curves vertcal curves are parabolc (dstorted): sag curve (concave) radus Rs crest curve (convex) radus Rc (stoppng sght Rc Rc,mn) add the mnmum rad of vertcal curves to the techncal report: Rc,mn... accordng to V from fg and fg (the smallest possble for stoppng sght) Rs,mn... accordng to V from fg and fg (the smallest allowed) Rs,mn and Rc,mn must be respected n the desgn!

6 Fg (scheme of crest curves) Fg (mnmum rad of crest curves) Fg (scheme of sag curves) Fg (mnmum rad of sag curves)

7 Insert and calculate vertcal curves (dmensons accordng to fg. 0180): Fg (vertcal curve basc dmensons) Fg (vertcal curve termnology)

8 Recommended procedure select t calculate Rs(c) accordng to the followng formulas: a) One-sded gradents (fg and fg. 0200) t R s(c) 1 R t 1 s(c) Fg a fg (vertcal curve one-sded gradents) b) Opposte drecton gradents (fg. 0210) t R s(c) 1 R t 1 s(c) Fg (vertcal curve opposte drecton gradents)

9 verfy (for all vertcal curves): R or R c R c, mn s R s,mn Rs or Rc desgn the greatest possble Formula for vertcal coordnate y of any pont of vertcal curve: 2 2 x t y ymax 2 R 2 R s(c) Process of plottng the second phase fg. 0100, fg and fg. 0250: Markng of gradents and vertcal algnment (ncludng chanage of all ponts A, BVC, PVI, EVC, B) fll n all the values accordng to the examples n fg. 0100, fg and fg Markng of horzontal algnment: Pay attenton to dfferent schemes for left-sded (fg. 0220) and rght-sded (fg. 0230) horzontal curve Descrpton of horzontal curves (R, c, L fg. 0240), transton curves (L, A fg. 0250), straght secton (L fg. 0250) and 6 ponts (A, TS, SC, CS, ST, B fg and fg. 0250) s(c) Fg (scheme for leftsded curve) Fg (scheme for rghtsded curve)

10 Fg (longtudnal profle example of central part)

11 Fg (longtudnal profle example of the end part)

12 Preparaton for cross-sectons, descrpton of vertcal axs (fg. 0100) measure terran elevaton (wth an accuracy of 2 decmal places) fll n accordng to the example n fg. 0250: In ponts A, BVC, PVI, EVC, B In ponts TS, SC, CS, ST In all ponts every 20 m Elaboraton of longtudnal profle 2 optons: (On graph paper) On a computer n CAD Colours n longtudnal profle fg. 0100: 1. black: vertcal and horzontal axs man chanage every 100 m (0.0; 0.4;...) base lne terran lne elevatons terran lne 2. red everythng else