MECHANICAL DESIGN TOOLS

Structural simulation erected storage tank with jacking system

<img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUpVw4maNqjhnYo3F0Uef64ytsANn4gjZc-4LDkj_0D4mQ5efUwMYYTsIWRYJ0ju3hAopFmENlYm-G5xRtllun9jj1z5fVowURp99YToKKH2Bw-hs30zVAs1UU5k9iuXE0KujMGBauD_8/s320/Load.png"/>
 
<div style="margin: 0in 0in 0pt; text-align: justify; text-indent: 0.5in;">
Common tank erection usually from bottom to top structure but sometimes in certain location its impossible to apply, for example at tank farm live plant which is hot work not allowed in certain elevation so other erection method should be developed in this condition such as application of water curtain, welding habitat etc. 
<div style="margin: 0in 0in 0pt; text-align: justify; text-indent: 0.5in;">
An alternative method is building it from top to bottom by using jacking equipment, in this posting I'm not going to discuss about the erection method since there are so many article and video in youtube with clear explanation, I’d like to share my previous experience how to decide required  qty of jacking tools base on structural simulation. 
 
PRELIMINARY DATA: 
Tank Spec:</div>
</div>
<ul>
<li>Roof type : Dome Roof </li>
<li>Diameter : 34747 mtrs </li>
<li>Total Shell Height : 23200 mtrs </li>
</ul>
Jacking tools spec: 
<ul>
<li>Each Jack capacity = 12 Ton </li>
<li>Max space between jack = 3.5mtrs (from manufacturer) </li>
<li>Max. actual safe wind load at lifting = 15 m/s </li>
</ul>
Other Data: 
<ul>
<li>Max Height allowed for hot work = 14 m </li>
<li>Wind speed at site = 35 m/s per year </li>
</ul>
<div class="fullpost">
SIMULATION DATA: 
Simulation model build in STAAD-PRO software with sequence as below:<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgK7jVar2urex-sbwZf_zZI2H5W8KdChfcyHAPdpAu8zWremzPEodQriFcNl7Lmhs-rU2rlQ9pG1xEyVKKbFj9dUlsW0TmtvPfvji_xnSB2MxDogmclKGdDnBQ2C04DHo0fZI6N1V39RC8/s1600/Jack_Sequence.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em; text-align: center;"><img border="0" height="226" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgK7jVar2urex-sbwZf_zZI2H5W8KdChfcyHAPdpAu8zWremzPEodQriFcNl7Lmhs-rU2rlQ9pG1xEyVKKbFj9dUlsW0TmtvPfvji_xnSB2MxDogmclKGdDnBQ2C04DHo0fZI6N1V39RC8/s320/Jack_Sequence.png" width="320" /></a> 
 
Jacking device layout inside of tank structure with qty = 34 divided equally at circumference 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQdtrgxxLbT0_4maJZtorVC1duwrNi4u8V5IO9uNbQcjS6AV-74_3XRKyDOfTtRb9che3n8vmjwBSNYWk02e4OXb2VKFUY7k7mHTQdoFZ2YVzAf9mRHTp-piF0w-MGZCXB4xNZvD3CZeo/s1600/Jack_Layout.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="234" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQdtrgxxLbT0_4maJZtorVC1duwrNi4u8V5IO9uNbQcjS6AV-74_3XRKyDOfTtRb9che3n8vmjwBSNYWk02e4OXb2VKFUY7k7mHTQdoFZ2YVzAf9mRHTp-piF0w-MGZCXB4xNZvD3CZeo/s320/Jack_Layout.png" width="320" /></a></div>
 
Shell Plate thickness arrangement: 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPV6TaNiO2aq9TbSFaL5tL1B4h4XIrB9yd3zENwsNWa1FEU4LyQSIqPJGi95tiStPiTii9_pUCCWerOKCxGY-KoYLfo61lVaRPHWGvEaQ52AQi2dkUh9F2pcmbqP0Y_70jpvvtm8kKc0Y/s1600/Tank+Plate+Arrangement.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPV6TaNiO2aq9TbSFaL5tL1B4h4XIrB9yd3zENwsNWa1FEU4LyQSIqPJGi95tiStPiTii9_pUCCWerOKCxGY-KoYLfo61lVaRPHWGvEaQ52AQi2dkUh9F2pcmbqP0Y_70jpvvtm8kKc0Y/s320/Tank+Plate+Arrangement.png" width="305" /></a></div>
 
Dead load of roof with all of appurtenance generate by manual calculate = 119546.5 kg, then additional weight of shell plate will generated by software. 
First erected structure by jack as per picture below: 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGwxFKkHN-Zh4YnQFXOr31-x6tTOZdwBmvoY2GdVmKpV_WLmnGBAY0z9bkALU_-hLoi39C-Agc2_FmxoSqZQGBU-GDfbS1zh07mzYjMJi2chlSzfF4uZvhs7Ig0cZaCqnv9J8x8XqZgAg/s1600/1st_lift.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="109" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGwxFKkHN-Zh4YnQFXOr31-x6tTOZdwBmvoY2GdVmKpV_WLmnGBAY0z9bkALU_-hLoi39C-Agc2_FmxoSqZQGBU-GDfbS1zh07mzYjMJi2chlSzfF4uZvhs7Ig0cZaCqnv9J8x8XqZgAg/s320/1st_lift.png" width="320" /></a></div>
 
 
DESIGN LOAD: 
<ul>
<li>Dead Load (DL) </li>
</ul>
Roof Load = Roof weight / Top angle Lenght 
<div style="margin: 0in 0in 0pt; text-align: justify; text-indent: 0.8in;">
= 119456.5/(3.14 x 34747) =1092 kg/m = 10706.42 N/m
</div>
 
<ul>
<li>Roof Life Load (Lr) </li>
</ul>
Roof life load as per API 650  
<div style="margin: 0in 0in 0pt; text-align: justify; text-indent: 1in;">
= 122.1 kg/sq. mtr (apply in top angle)</div>
 
Roof life  load = 122 x roof area / top angle length 


 
<div style="margin: 0in 0in 0pt; text-align: justify; text-indent: 1in;">
=122 x 1042.97 / 109.5 = 1163 kg/m = 11404.97 N/m</div>
</div>
 
<ul>
<li>Wind Load </li>
</ul>
    Wind pressure Refer to ASCE, use below equation for height variation                                                                            
    qz    =    0.613 Kz Kzt Kd V2      (ASCE 7-10 Para. 27.3.2)                
                                                                                
    P    =    q G Cp - qi (G Cpi)       (ASCE 7-10 Para. 27.4.1)                 
Result as per below table : 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtJNu4B-UYk_soxCCG-MRhN6Y9wR11JBh9b4WGbLKpQQLRJfMaztrnsgI5mjZowH3Hfa00AGTXNaSkUZmviODWQ_ZR5nrNQ6OhJAn9KfAOZ-1edHIXIyc0vTr7lEGH7EHpWlcCLoDG4uU/s1600/table+wind.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="142" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtJNu4B-UYk_soxCCG-MRhN6Y9wR11JBh9b4WGbLKpQQLRJfMaztrnsgI5mjZowH3Hfa00AGTXNaSkUZmviODWQ_ZR5nrNQ6OhJAn9KfAOZ-1edHIXIyc0vTr7lEGH7EHpWlcCLoDG4uU/s320/table+wind.png" width="320" /></a></div>
 
With simplification in applying load as hidrostatc load, vary lineary as per height function 
Load Model: 
 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUpVw4maNqjhnYo3F0Uef64ytsANn4gjZc-4LDkj_0D4mQ5efUwMYYTsIWRYJ0ju3hAopFmENlYm-G5xRtllun9jj1z5fVowURp99YToKKH2Bw-hs30zVAs1UU5k9iuXE0KujMGBauD_8/s1600/Load.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="191" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUpVw4maNqjhnYo3F0Uef64ytsANn4gjZc-4LDkj_0D4mQ5efUwMYYTsIWRYJ0ju3hAopFmENlYm-G5xRtllun9jj1z5fVowURp99YToKKH2Bw-hs30zVAs1UU5k9iuXE0KujMGBauD_8/s320/Load.png" width="320" /></a></div>
    
<ul>
<li>Combination Load: </li>
</ul>
Shell ring plate analysed with load combination for Allowable Stress Design as per ASCE 7-10 para. 2.4
 
<ol>
<li>DL </li>
<li>DL + Lr </li>
<li>DL + 0.6 W </li>
<li>DL + 0.75(0.6W) + 0.75Lr </li>
</ol>
Design criteria to be applied with max. Von misses equivalent stress compare with yield strength of plate material 
Result for plate stress distribution by STAAD PRO for each combination load : 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-SrOM7QIRX3b8lyylN1DQn_76xV5DUqS84EB1E04Y7mIoOkxCTYOKsi32DRwkWzuBdBCfNOnhCodBVmjgFRYdqa8iQTGx98lCvZZOB83CnbCZx7KTTa3cw1NFMHbAYKhOgbMGdjCErfQ/s1600/Stress+dist.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-SrOM7QIRX3b8lyylN1DQn_76xV5DUqS84EB1E04Y7mIoOkxCTYOKsi32DRwkWzuBdBCfNOnhCodBVmjgFRYdqa8iQTGx98lCvZZOB83CnbCZx7KTTa3cw1NFMHbAYKhOgbMGdjCErfQ/s640/Stress+dist.png" width="416" /></a></div>
 
<a href="https://www.blogger.com/$image9.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image21.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image25.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image17.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image12.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image13.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image5[1].png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image2.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image5.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$tank13.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$clip_image0024.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/blogger.g?blogID=5587740760374181364" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$clip_image0024.gif" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$clip_image0024.gif" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a>ANALYSIS RESULT: 
<ul>
<li>Max. Plate Stress : </li>
</ul>
Max Stress caused by Load Combination no.6 DL + LR with result find 
11.8 Mpa < 205/2 Mpa (Plate Yield Strength/Safety Factor) ==> OK 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLxLPAD9AiIDgfwBCtqx7lyGoUnyI59cTgKrtk1t3LvO_weQI3ySwLKsVapCSPnmSzyWtJPjJy885RNO4HcPyShjwaSUuzLTtQ4K0pavN2bGl2QEQFAdtXxJK30vOJNQD4SICtDXTZ3Ns/s1600/Max+stress.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="183" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLxLPAD9AiIDgfwBCtqx7lyGoUnyI59cTgKrtk1t3LvO_weQI3ySwLKsVapCSPnmSzyWtJPjJy885RNO4HcPyShjwaSUuzLTtQ4K0pavN2bGl2QEQFAdtXxJK30vOJNQD4SICtDXTZ3Ns/s320/Max+stress.png" width="320" /></a></div>
 
<ul>
<li>Reaction Force </li>
</ul>
Max. Reaction Force caused in last lifting stage 8 with result find 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjU8kJkdYUf3TM61MIR6DKmRKa8IiwWKY2xe_BpIhmn-AHI0MjsWZAQ4mKS7mTWCEp8cHBmTrr2bWwTOzxSLjtUlPoqtpbC4ajf9zCvuATBPekU2V4UapVZqSpvAdwaUHW__eV8nSsAp24/s1600/Reaction+Result1.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="70" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjU8kJkdYUf3TM61MIR6DKmRKa8IiwWKY2xe_BpIhmn-AHI0MjsWZAQ4mKS7mTWCEp8cHBmTrr2bWwTOzxSLjtUlPoqtpbC4ajf9zCvuATBPekU2V4UapVZqSpvAdwaUHW__eV8nSsAp24/s320/Reaction+Result1.png" width="320" /></a></div>
 
Max. vertical force that carry by jack device = 11.95 ≤ 12 Ton ==> OK 
(below max. jack capacity) 
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxYNfmwsGpbx9_hPrHvGpF4jh0jiblu0ORkq4QT3qbRnK13_OlDWBAjSPaBCtXD2qElsFjymFuiI9caKD0pOQ1J-tH5PQNbKNQlwTPdgLfhGwY0Dsmjcsg_eVeRf7U1jPKwbCoBdmZefU/s1600/Reaction+Result2.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="259" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxYNfmwsGpbx9_hPrHvGpF4jh0jiblu0ORkq4QT3qbRnK13_OlDWBAjSPaBCtXD2qElsFjymFuiI9caKD0pOQ1J-tH5PQNbKNQlwTPdgLfhGwY0Dsmjcsg_eVeRf7U1jPKwbCoBdmZefU/s320/Reaction+Result2.png" width="320" /></a><a href="https://www.blogger.com/$clip_image0024.gif" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$clip_image0024.gif" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/blogger.g?blogID=5587740760374181364" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$clip_image0024.jpg" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$tank13.png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image5.png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image2.png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image5[1].png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image13.png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image12.png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image17.png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image25.png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image21.png" style="margin-left: 1em; margin-right: 1em;"></a><a href="https://www.blogger.com/$image9.png" style="margin-left: 1em; margin-right: 1em;"></a></div>
 
SUMMARY: 
<ol>
<li>Plate stress in elastic region for every combination load, no indication shell plate will deform in plasticity since von misses equivalent stress result still below yield stress material </li>
<li>Generated Max. reaction force smaller than max. capacity of jacking device </li>
<li>Number of jacking device = 34 ea are sufficient to support stability and integrity of structure with considering structure weight and additional wind load </li>
</ol>

Structural simulation erected storage tank with jacking system

Common tank erection usually from bottom to top structure but sometimes in certain location its impossible to apply, for example at tank farm live plant which is hot work not allowed in certain eleva…

24 Aug 2016

Eurocode footbridge design

<div style="margin: 0in 0in 0pt; text-align: justify; text-indent: 0.5in;">
Footbridge as an access for passenger to step in floating dock are need to consider its strength and integrity so can accomodate any potential unsafe situation that would happend for example in peak season when passengger are overloaded has to be considered in design. 
Below pict. Are General arrangement for floating dock service with preliminary bridge design. The bridge are flexible mounted so can be follow vertical movement of pontoon as tidal effect, there are other structure that holding pontoon to prevent horizontal movement. 
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWd6lohRhJGxEHtyj8gT-V2pu9kAkVMcSICw-Ryqk9FGKzcbv6glHTFToCAe4sc9HBWlv_R66-PcXt4FSp4l-FZ9S7hswmKPX3Q9Li95wyesjtS7D15hK9WHV8dHl3fhTQQskm5Dpuz1k/s1600-h/image%25255B8%25255D.png"><img alt="image" border="0" height="184" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbb5SCtZK1gDrKhdIBqIg4qrvB8o3vS4KG71DH8LRcq2np2x1oBpPjdLvjhXzHdxI0RS9yvyE0lkiM7srK8zQmQsJa9j2uYLvGHYoV-8tfBi6A49pdgyIuFV08NFQTrnqhtxlhbbYU9ZI/?imgmax=800" style="background-image: none; border-bottom: 0px; border-left: 0px; border-right: 0px; border-top: 0px; display: block; float: none; margin: 0px auto 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="image" width="299" /></a> 
 
<div class="fullpost">
As per project spec, the bridge consist of aluminium framebase structure with steel handrailing also several condition need to be fullfilled. 
<div style="margin: 0in 0in 0pt; text-align: justify; text-indent: 0.0in;">
 
<ol>
<li>The bridge are assembled from two structure with hinge connection for mobility reason</li>
<li>Total bridge weight not more than 1Ton since the availabe winch at site has SWL 1Ton for bridge lifting purpose.</li>
<li>Design optimization only allowed at framebase section.</li>
</ol>
</div>
</div>
</div>
Bridge modeling : 
The bridge are modeled in 3D space structure. 
<blockquote>
Bridge Section 1                                                                                        Bridge Section 2</blockquote>
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6vL73Jjngvuf3-1-R23W0Sz2pkX1J8GknO5t1juFQsTWBjrfREGPc86tHuV9uaqF0nYTyhKlcYuT1_KXLLewvseCkp4iAc1sFBzsTagcg96IALbsnCcxVf4-pXUeNcQIl_aDhHfz37ME/s1600-h/clip_image004%25255B6%25255D.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img alt="clip_image004" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1oFDgESszs-XlbnVuGgBJv2xqxLofVSd3D8Dn_Pvw2f9r2R1eMyV3J-e5XX-JAyx-grlSjtPGH7T7TVUiZWVXtTMC4Qnv0F8TXcryTKzpjzTR5AJu06pYNklZY_5W9Ohl2wcOiGOwesQ/?imgmax=800" style="background-image: none; border-width: 0px; display: inline; margin: 0px 0px 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="clip_image004" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEicPGniUwdSCnLvZ8dnsINciVPqLCsxAPDZXh4ES-sZUR55QoX5Uq5xQjHIcvyHMbfHnVKSbRSSeVsWmmuURxO94TX9IPyg4GHMjxvHpPgEPRq-r7Dzi99bfnmobuTL3vPdj3TL_LpFip0/s1600-h/clip_image002%25255B20%25255D.jpg"><img alt="clip_image002" border="0" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhoE6tgriGPjTe4nIFeNs_hG4atvgZuiCZ78Bi563mHtrjexa0Hr9xt5t7EHgIyYzQrPjZp0IVBccgEyUT-7skj0Bd9UayQN1t4lIChp9J1v6uSH8m-B4U0a2-rd6X4NiaiKSu0khZO5IU/?imgmax=800" style="background-image: none; border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: inline; margin: 0px 0px 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="clip_image002" width="204" /></a> 
<blockquote>
<div align="center">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhR9ofzkimZQa6Q7ph03tUFWZW1Ct_E2ZzecJh6QiJ1pYaDL8mL-SwB8vuLMJGQbe99BICeYgMoq59JQUqxbBnYV9b0kpo9daUTVJ5umsUAPOfKvAPxLk5AFcQjAAfs9TamBnfe3sswG4I/s1600-h/image%25255B11%25255D.png"><img alt="image" border="0" height="284" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiguYtlm6KW0JXivEGBF7Fb2wZ5E_sh1G8EgXm3bsFfqm71ZqwqbGNAyKGOhdRVTleyktOHFDnRg0dWCIxp7bZbla1pJq0gcrsxgbedfCSbJwMpSnf5isYIHiGKMKy1Su-nLz57fmRFsaY/?imgmax=800" style="background-image: none; border-width: 0px; display: block; float: none; margin: 0px auto 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="image" width="400" /></a></div>
</blockquote>
<blockquote>
<div align="center">
Bridge Assembly</div>
</blockquote>
Update general arrangement by applying new design structure: 
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgS6gXcgJcvvoJpGW3ekkDqyO2FGillxFHtsljdZsD-Oc-dg8rLg5i0CxT6j6RijF4nw6q3iLYADhL90vtw7wE9orwtwxDDKND6T7-GukwMZ7rcpZINL440r-Y9eoWuu6PcU08KQbmpCMg/s1600-h/image%25255B12%25255D.png"><img alt="image" border="0" height="184" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi1ydhGU3-TKJlEefzqGxJXEiUc6TEWPh6Coqd1b9yAoNYl7ruUiObzPjHZCJpQ4rE1VQFEMc1MePU8WmAWdjj8aImidFu5Yn1JkuiePHcXgjaWFxj_oudehnOqa-Aj4ozT8XhAwKFbY6w/?imgmax=800" style="background-image: none; border-bottom: 0px; border-left: 0px; border-right: 0px; border-top: 0px; display: block; float: none; margin: 0px auto 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="image" width="296" /></a> 
Note: There are possibility colliding between bridge frame structure with pontoon handrail. 
Structure size and weight: 
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgsrce0r6ToMgUsu5MZ6B9n9ba7DveR0SYt0zAmmvvJWMvgZKv16KY2zqpPk0Y_2Ymfff6U1h7sucOsqzPBWufQaok0BvuH7FZ5oH1828KkEeaawmylJwGp7yXvP1S8h4UwVDYXOH58Ko/s1600-h/image%25255B163%25255D.png"><img alt="image" border="0" height="112" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJ3LMbS_Cm2zPfq8zDwB2aUYCC4xJufGFzUjqQZWijVtqQ1JFrfnjtLs78AHxd33O9ThV4dnY_54eOvciFySXdltZ9p1UqNSHctB3Odje8pXDtFkZvA7sYikwhbXA_MnSNHwgz0ff9WhU/?imgmax=800" style="background-image: none; border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: inline; margin: 0px 0px 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="image" width="404" /></a> 
Bridge portion at quay use wheel support and hinge connected to pontoon walkway 
PICT.3 
Bridge hinge for this model assume as fix node and the other have release nodes behaviour at splice area. 
PICT.4 
There are several bridge code that can be use as guidance but eurocode has more conservatife approach for public fasilities related with safety service. The design parameter refer to eurocode are below: 
Applied load : 
1. Selfweight of bridge structure 
2. Trafic load (See EN 1991-2 Part. 5) 
- Uniform distributed load 5 kN/m2 applied perpendicular to floor surface 
3. Wind load (See EN 1991-1-4) 
- With site data for wind are: 
<ul>
<li>Air Density (r) = 1.25 kg/m3 </li>
<li>Wind Velocity (Vb) = 10.3 m/s </li>
</ul>
- Calculated wind force : 
<ul>
<li>Peak velocity pressure (q(z)) = 0.16 kN/m2 </li>
<li>Wind force at direction (Fw,i) : <ul>
<li>Perpendicular to the bridge = 1.14 kN </li>
<li>Paralel to the bridge = 0.94 kN </li>
<li>Vertical direction = 0.28 kN </li>
</ul>
</li>
</ul>
Load combination : 
Load combination will refer to EN 1990 with using Ultimate Limit State (ULS) and Service Limit State (SLS), since only wind that considered as environmental load so load factor can be simplified as per below: 
<blockquote>
1. Service Limit State</blockquote>
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWVHHZzAjpq3BB5hw4ZQMcwq2YlVbLC_nJadeR6S7IeYoR9_pInpF-6XX8LqQ_PqW6SGWeJr8LmACuopeK8MP8Fho_xdpEM0XMIXznGhPx70SYEdAW9LXqGAxho3pzNjc2eg7pqJFLWGs/s1600-h/clip_image008%25255B3%25255D.jpg"><img alt="clip_image008" border="0" height="68" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTfmZSqBnOoePB_ZCp5nGCRljZ04t_3aZFoIf6BulHNad22rZ2BnOI1Q_ybNTlQJZaS19nxsDUBq29_5J3JLmvwgakh-BPt5vIfnjX7m5_dYnydnyHnn4qfVxxtMyBnU6c8qBSZ0VSDMg/?imgmax=800" style="background-image: none; border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: inline; margin: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="clip_image008" width="244" /></a> 
<blockquote>
2. Ultimate Limit state</blockquote>
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgTNLIV7Td77V7H4KwdiooIixy4T3zZT-lxsbEvrn7kbIxwaNCL_efI3gecYXr_h2bsjaA_m8CrAE61YO3dDPCSofX6V2mb0huTT0-M_3mchtnN6QdHkRCCVr_uK1myq81qQPiBlkFrfA/s1600-h/clip_image010%25255B3%25255D.gif"><img alt="clip_image010" border="0" height="66" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEghXKyOEURXgaisnnNs8n9k9rX88x3UC0IyDIHRE4Nk3LI288NMk1p6K9XUJ5geMYCoQ92ZVfl9mab2wvrN-Lz1BUbIQOTJ-Dm0SvjG7A2kEyZmYwF-qwDdEWdkbCt7ZuADsTdoM4cvEK0/?imgmax=800" style="background-image: none; border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: inline; margin: 0px 0px 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="clip_image010" width="244" /></a> 
Acceptance criteria : 
1. Stress material 
For material propertied for aluminium structure refer to EN 1999 
<table border="0" cellpadding="2" cellspacing="0" style="width: 400px;"><tbody>
<tr> <td valign="top" width="178">- Material</td> <td valign="top" width="11">:</td> <td valign="top" width="106">AL 6061 T6</td> <td valign="top" width="103"></td> </tr>
<tr> <td valign="top" width="178">- Density</td> <td valign="top" width="11">:</td> <td valign="top" width="106">2712.6</td> <td valign="top" width="103">kg/m3</td> </tr>
<tr> <td valign="top" width="178">- Yield Strength (fy)</td> <td valign="top" width="11">:</td> <td valign="top" width="106">240</td> <td valign="top" width="103">Mpa</td> </tr>
<tr> <td valign="top" width="178">- Ultimate Strength (fu)</td> <td valign="top" width="11">:</td> <td valign="top" width="106">290</td> <td valign="top" width="103">Mpa</td> </tr>
<tr> <td valign="top" width="178">- Modulus of elasticity (E)</td> <td valign="top" width="11">:</td> <td valign="top" width="106">68900</td> <td valign="top" width="103">Mpa</td> </tr>
<tr> <td valign="top" width="178">- Shear Modulus (G)</td> <td valign="top" width="11">:</td> <td valign="top" width="106">26000</td> <td valign="top" width="103">Mpa</td> </tr>
<tr> <td valign="top" width="178">- Poisson’s Ratio</td> <td valign="top" width="11">:</td> <td valign="top" width="106">0.33</td> <td valign="top" width="103"></td> </tr>
</tbody></table>
 
Permissible stress for tension, compression and bending members: 
<blockquote>
sperm = fy/ym = 240 Mpa</blockquote>
Permissible shear stress : 
<blockquote>
tperm = fy/(ymxÖ3) = 139 Mpa</blockquote>
Where : 
<blockquote>
fy= Yield stress of material</blockquote>
<blockquote>
ym= material factor = 1.0</blockquote>
2. Deflection 
With refference to EN 1990-Annex A1.4 limits for vertical deflections according to figure A1.1 should be specified for each project and agreed with the client. Due to no specified maximum vertical deflection by client, maximum vertical deflection in SLS cases in the middle of bridge span assumed as L/250 = 9500mm/250 = 38mm 
 
3. Frequency 
With assumption: 
1. No horizontal force acting on the brige because of pontoon movement 
2. Analysis structural in frame-base, the handrail and any other appurtenance only contribute self-weight loading. 
 
Analysis result : 
1. Max stress generated at ULS cases are 137.2 Mpa at L.C 1.2 still below permissible 
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGr0cAtKFT_P4Gw19WHh3T3W35aeZGEERtmbVN0K-nBPqV61ifDYuUqCa1ZeKlxlLqQdVajojb7xzKjN1DKpZyMImFMK5DHVJwLLCeKbyJhDzIqDFKkjiURhL6GFSoK5Xmx_D_z_J9tdM/s1600-h/image%25255B212%25255D.png"><img alt="image" border="0" height="244" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3_Cb_CI8RxG-Kne__1pYiDmjh7f5_aiXAWh6NOme9u0MEvoCX8NWL3hyphenhyphenA7LOA7HEB9RmCBYWVDHAL5HX7eTZ1Yc5dedvEbeM-aGHSVdfQ8xglgz3WrK004ECeNJpRR-ytoQwgm2IXAxE/?imgmax=800" style="background-image: none; border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: block; float: none; margin: 0px auto 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="image" width="304" /></a> 
2. Max deflection at SLS cases are 16.7mm at L.C 1.2 still below allowable deflection limit 
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6PLgoZmt8NfeOfx4VN56XsfLo9EGWig-BW9zFnzXw2Y9toGVle2iq3sm1TSyFuOukv6Q_BbqXnPmg_FaKWEz0ZwB8goNcD1DYJtJ2W6edH6eumvMmpY2FKG7dNFOFuADJZH1u-msj0Zs/s1600-h/image%25255B216%25255D.png"><img alt="image" border="0" height="239" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhW_A1FXSVoLYjxfUfAuCqiLJrZ6aHTKWelgywnG5OeLN3OTGjSXxFSD2tZOGBLZoosqIElAc-jmLqmTIscZQqE5alrbLwrrW8JPF1ylr3x3bJYESerHetlbKHdwWRJgHFkhN1-YdlpZt4/?imgmax=800" style="background-image: none; border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: block; float: none; margin: 0px auto 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="image" width="304" /></a> 
3. Frequency at mode shape 1 is 2.97 hz still in alowable limit 
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhN8chZvSwA0aiSSpNATDiL5N2p1Xyj95Kvzt6Cd8kFRKLR6orHk-ZLH8sIThClJMmVYKWdIVfHrKXyVcvZQIxH1EnMyYNwx53cX8iae8vEr1v2U9IKmU6lmwIYxbrxFr7t0U5sangxODM/s1600-h/image%25255B220%25255D.png"><img alt="image" border="0" height="298" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSTzT-U15d98BwqtQScY3HCCKovA9W4Qte8VZMOdJCpaAZgQtTCfJM33o_2IRmr8bEbbXmr-BxKmgyk3m9DDQdG9w-xQTKkJ7bl1wfBmAn08jFexKnj8Z88bhUKox42hN2mXG_QAGp6Ig/?imgmax=800" style="background-image: none; border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: block; float: none; margin: 0px auto 5px; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="image" width="304" /></a> 
New foot-bridge structure design comply with Eurocode

Eurocode footbridge design

Footbridge as an access for passenger to step in floating dock are need to consider its strength and integrity so can accomodate any potential unsafe situation that would happend for example in peak …

22 Apr 2016

Load more posts

MECHANICAL DESIGN TOOLS

Structural simulation erected storage tank with jacking system

Eurocode footbridge design

Popular

Comments

Archive