Jacky

Hi team a) Basic question. I'm not sure what the cross section of the bridge is suppose to look like. Is it suppose to look like picture below? If so, im not sure how the xs_bridge.csv is suppose to represent this shape where in the csv: H=37.612, W=0 H=37.7, W=4.86 etc. It does not seem to be 4.86m wide at H=37.7m. Even if it is, is it suppose to be symmetrical about some base point? How would you actually plot the xs given that the xs.csv is in H-W format. b) Is the below loss coefficient table lc_bridge.csv suppose to represent the above bridge cross section (i.e. between RL37-RL38.9, there are no piers hence LC=0 and LC would be determined from hydraulics of bridge waterways; above RL39.9, there are 3 piers hence LC=0.24)? Unsure why there is separation between RL39 and RL39.9 with different LC. c) For option 2: 1D bridge with 1D weir, the xs_weir.csv shows width of weir (i.e. distance that is perpendicular to flow) of 45m however the xs_bridge.csv shows bridge width of 54m. Is the width of weir for bridge overflow suppose to equal width of bridge? d) For option 3: layered flow construction, The intention is that a FLC of 0.25 is divided by 12m. Is this suppose to be the length parallel to direction of flow? if it is, the lfcsh_R.shp length seems to be approx 15m long rather than 12m as shown in picture above. Am I correct? e) In the check file M06_5m_FINB3_001_lfcsh_uvpt_check_P.shp, the resultant layer 1 FLC is 0.1 shown below. How is 0.1 calculated from a total FLC of 0.25 and having 3 grid cells (5x5) parallel to direction of flow (shown below)? f) In the 2d_lfcsh_m06_bridge_001_P.shp, the invert of the point is set at RL39 with the exception of 2 points with invert=99999 (which I believe means to use existing zpt elevations). Is there a reason invert RL is set at RL39 (i.e being lower than existing zpt elevations) elsewhere other than channel centre? g) HX boundary condition needs to be digitised perpendicular to flow as it assigns a constant water level to the HX line. In the picture below, although only 200mm difference between 40.37 to 40.57, lets say we exaggerate that difference and imagine the road sloping steeply to the left. I presume it would be inappropriate to digitise the HX line as shown in this exaggerated case. How would we then digitise the HX line given that water could fall towards the left as well as overtopping the enbankment? h) This module uses a polygon-lfcsh_R and points-lfcsh_P. The technical memo (https://www.tuflow.com/Download/Technical_Memos/Modelling Bridge Piers in 2D using TUFLOW.pdf) uses a line-lfcsh_L i believe. Could this module be modelled like the technical memo using a line-lfcsh in front of each single pier and vice versa could the technical memo be modelled using polygon-lfcsh? Are they interchangeable? I understand polygon-lfcsh can create sloping decks but in this module, it is flat. If i were to model this module using line-lfcsh, would I remove the polygon and digitise a single line upstream of bridge with Layer 1 FLC=0.25 (as that is the total FLC for the polygon), Layer 2 FLC=1.56, Layer 3 FLC=0.72? Is this the correct approach? Thanks! in advance for answering these questions thats been bugging me for a while now. Jack

2) hm interestingly, I have noticed that how I digitise the channel in between 2 xs does affect the 2d dem check file in the end. Although it probably doesnt matter because that area gets code = 0 anyway.

omg, thank you so much. Clarifies everything. I've been pulling my hair out for the longest time ever trying to find out why triangles arent showing! These are the tips and tricks that are never documented in manuals and can only known be from experience and theyre the ones thats always so frustrating to figure out!

Hi, several questions thats confusing me 1) When digitising 1d_nwk_M04_channels_001_L.shp inbetween 1d_xs, does it matter which 1d_xs vertex we snap onto? 2) I digitised 1d_nwk_m04_channels_001_L.shp by following the gully of the creek. What happens if I dont follow the gully shape but I still snap onto the same 1d_xs vertex as if I were following the gully shape? i.e. Does tuflow consider the bends of the 1d_nwk_channel? 3) The 1d_xs_M04_Cxxx.csv files starts with x=0 z=41 to x=10 z=30 (say), how does TUFLOW know which gis vertex corresponds to x=0 z=41? Is it based on direction in which 1d_xs is drawn where the first gis vertex corresponds to x=0 and last gis vertex corresponds to x=10? 3a) What happens if total chainage of .csv (i.e. 10-0=10) dont equal length of gis line? how does TUFLOW know which gis vertex cooresponds to x=0 and x=10? 4) We will need THICK lines for 2d_bc_HX breakline. Where have we specified THICK in the 2d_bc_M04_HX_001_L breakline? Or is it automatically assumed THICK when using read gis z hx line max == 5) CN line connects from the node of 1d_nwk_channel to the vertex of 2d_bc_hx. The CN line seems to overlap the 1d_xs line but not entirely. Does it matter which vertex on HX line the CN line connects to? much thanks Jack

i have this same problem.. any help?