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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link="#0563C1" vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Robert,<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>This could be a scenario where an instrument guided pulling test could help. Pull the tree before the root cutting to establish the baseline stability of the tree and then pull the same tree to the same load after and see if the reactions are different. The resultant stability after root cutting can be modelled with the data collected during the test. That way there is no longer guessing, you know if the tree is stable or not and if not, what crown reduction may be required to achieve a reasonable safety factor.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>I am a member of the SAG Baumstaik group in Europe, an association of tree risk experts , many long time practitioners of the elasto-inclino pulling method initiated by Lothar Wessolly and Gunther Sinn. I have been doing these pulling tests in North America since 2004 and have done over a 1000 tests. <o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>If there is going to be a one-sided straight line excavation we often talk about the critical distance being 1.5 X DBH. Any closer and stability will likely be compromised. Outside that at 1.5 x dbh you still have a significant proportion of the anchorage-associated structural roots and the tree may well stay stable. The affect on the future health of the tree is another matter and the loss of soil volume, fine root system and good rooting space may be a significant matter that also needs to be factored in. This is the arboricultural consultant side of things, not for the engineer to decide…<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>But of course it all depends on the specific arrangement of the structural roots on the tree you are interested in. In an urban situation there may be no roots in some directions and then an unexpected mass of roots in another location.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>We do need to stop the engineers from taking “simple” and drastic measures to work around a tree. We can identify the constraints and they can work with them. Its just easier, and historically what they are used to, to just cut the tree and get it out of the way…but we know that it is not simple and that when they cavalierly cut down the tree, the community loses a significant asset and will not be able to adequately replace it for many, many years…if at all. I doubt the success of much of the proposed compensation planting I have seen over the years.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>The engineers are amazing at solving problems and finding solutions…when there is a gas main they have to work around it and they do. Maybe we need to call all structural roots “gas mains” to get their attention. Then they will carefully and successfully work around them.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>If we don’t stand up to the engineers, they will keep the straight line thinking mentality forever.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Since the tree pulling test is an engineering based approach, we have often had success talking to engineers with our data. They speak the same language then.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Maybe this might help?<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Cheers,<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Philip<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b><span lang=EN-US style='mso-fareast-language:EN-CA'>Philip van Wassenaer, B.SC., MFC<o:p></o:p></span></b></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Urban Forest Innovations Inc.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>1331 Northaven Drive<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Mississauga ON L5G 4E8<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='mso-fareast-language:EN-CA'>Tel: (905) 274-1022<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='mso-fareast-language:EN-CA'>Cell: (647) 221-3046<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='mso-fareast-language:EN-CA'>Fax: (905) 274-2170<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-CA'><img width=153 height=73 style='width:1.5937in;height:.7604in' id="Picture_x0020_2" src="cid:image001.jpg@01D90008.7318BE00" alt="UFI new logo very small"><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-CA'><a href="http://www.urbanforestinnovations.com/"><span style='color:blue'>www.urbanforestinnovations.com</span></a><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='mso-fareast-language:EN-CA'>From:</span></b><span lang=EN-US style='mso-fareast-language:EN-CA'> CANUFNET <canufnet-bounces@list.web.net> <b>On Behalf Of </b>Liveanu, Robert via CANUFNET<br><b>Sent:</b> November 24, 2022 12:29 PM<br><b>To:</b> Canadian Urban Forest Network <canufnet@list.web.net><br><b>Cc:</b> Liveanu, Robert <r.liveanu@laval.ca><br><b>Subject:</b> [CANUFNET] Normes de sécurité concernant l'excavation et les arbres / Safety standards for trees and excavation<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=FR-CA>Bonjour-Hi<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR-CA>English follows below.<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR-CA>Est-ce que quelqu'un sait s'il existe une norme CNESST spécifique en lien avec les excavations à proximité des arbres? Nous avons un cas où les ingénieurs exigent l’abattage d’un arbre comme mesure de sécurité pour les travailleurs, tandis qu’à la Foresterie, nous sommes d’opinion que compte tenu de l’essence et le DHP de l’arbre, et la distance et nature de l’excavation, l’ancrage de l’arbre ne sera pas compromis, surtout si l’effort (peut-être superflu) est mis pour soutenir l’arbre <a href="https://www.ebing.ca/EBing-Projet-Support-de-poteaux-3.jpg">comme dans cette photo-ci</a>. Le problème se présente puisqu’à notre connaissance, la norme du CNESST concernant les arbres est une approche unique qui traite les arbres comme un poteau ou lampadaire, peu importe l’essence, son DHP, l’environnement, etc.<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA>___<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR-CA>Hello,<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA><o:p> </o:p></span></p><p class=MsoNormal>This age-old question is mostly targeted to Quebec professionals, but any insight from other provinces is appreciated as well as it’ll be interesting to compare. Does anyone know if there is a specific CNESST – Quebec’s occupational health and safety governing body – standard related to excavations near trees? Or what does your own province’s safety body have to say? We have a case where the city engineers are asking to remove a tree as a safety measure for the workers, while at the Forestry department we’re of the opinion that given the species and DBH of the tree, and the distance and nature of the excavation, the stability of the tree wouldn’t be compromised, especially if the (perhaps superfluous) effort is put into supporting the tree <a href="https://www.ebing.ca/EBing-Projet-Support-de-poteaux-3.jpg">as in this photo</a>. The problem arises because, to our knowledge, the CNESST standard for trees is a one-size-fits-all approach that treats trees like a pole or lamp post, regardless of the species, DBH, its growing environment, etc.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Merci, thank you!<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=FR-CA style='color:black;mso-fareast-language:EN-CA'>___<o:p></o:p></span></p><p class=MsoNormal><b><span lang=FR-CA style='font-size:12.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-CA'>Robert Liveanu, </span></b><span lang=FR-CA style='font-size:8.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-CA'>MFC, B.Sc.<o:p></o:p></span></p><p class=MsoNormal><i><span lang=FR-CA style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-CA'>Arboriculteur certifié de l’ISA<o:p></o:p></span></i></p><p class=MsoNormal><span lang=FR-CA style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-CA'>Technicien à la foresterie<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-CA'>Division Foresterie & Horticulture<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-CA'>Service des travaux publics<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-CA'>Tél. 450-978-6888 poste 4775<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA style='color:black;mso-fareast-language:EN-CA'><a href="https://can01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.laval.ca%2F&data=04%7C01%7Cmy.tremblay%40laval.ca%7Cec3b888e0037403d339708d8cf70014d%7C15ebd2ebb8cf40dd8e2bb2e67abb40ef%7C0%7C0%7C637487427315023800%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=YGbFwWfkPV1mwBIXvoyFz0MKfMe2vw0sbrYL09bU5n0%3D&reserved=0"><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>www.lavalca</span></a></span><span lang=FR-CA style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-CA'><o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA style='color:#1F497D;mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman",serif;color:blue;mso-fareast-language:EN-CA'><img border=0 width=96 height=35 style='width:1.0in;height:.3645in' id="_x0000_i1025" src="cid:image001png@01D8FFFE.264AEC10" alt="logo_laval_couleur"></span><span lang=FR-CA style='mso-fareast-language:EN-CA'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>