[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-650658-105":59,"doc-detail-650658-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","typical-elevation-on-underpinning-sections-engineering-notes-for-excavation-and-concrete-requirements","TYPICAL ELEVATION ON UNDERPINNING SECTIONS - engineering notes for excavation and concrete requirements","","Engineering notes provide detailed requirements for under-pinning works, excavation methods, and structural materials. They specify hand-dig or light mechanical excavation, protection and support of existing services, allowable ground bearing pressure checks, and foundation depths aligned with NHBC practice. The document defines RC35 and GEN 3 concrete mixes, reinforcement mesh lap requirements, well-compaction and blinding with sand, sequencing limits for under-pinning legs, cover and support during casting, and design/approval responsibilities for fabrication and connections. It also sets steelwork grade, bolt grade, welding fillet standards, and lateral restraint provisions.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/typical-elevation-on-underpinning-sections-engineering-notes-for-excavation-and-concrete-requirements/650658/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/typical-elevation-on-underpinning-sections-engineering-notes-for-excavation-and-concrete-requirements/650658.png","ImageObject",300,407,{"name":92,"@type":93},"นรินทร์","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-10-24",true,{"@type":102,"interactionType":103,"userInteractionCount":81},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What excavation methods are permitted for the underpinning works?","Question",{"text":112,"@type":113},"All excavation must be either hand dug or carried out by light mechanical excavator as approved by the engineer.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"What concrete mixes and reinforcement requirements are specified?",{"text":117,"@type":113},"Unreinforced foundations use designated mix GEN 3(20N) and reinforced slabs use RC35 grade concrete to the referenced standards. Mesh fabric must meet specified lap and cover requirements, and concrete for pinning uses semi-dry rammed hardcore blinding with sand.",{"name":119,"@type":110,"acceptedAnswer":120},"How should underpinning legs be sequenced and limited in length?",{"text":121,"@type":113},"Underpinning must be carried out in sequence as shown on plan, with maximum underpinning length of 1000mm and legs completed following the stated timing between adjacent stages.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},650658,1792836273,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":81,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":8,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":129,"read_time":81},2336475104957,"https://ap-avatar.wpscdn.com/avatar/22000c4c6bd8a5076e1?x-image-process=image/resize,m_fixed,w_180,h_180&k=1787554080175789136","NOTES:  \n1.TO BE READ IN CONJUNCTION WITH ALL OTHER RELEVANT DETAILS AND DRAWINGS ANDCALCULATION SHEETS  \n1.ALL EXCAVATION IS TO BE EITHER HAND DUG OR BY LIGHT MECHANICALEXCAVATOR AS APPROVED BY THE ENGINEER.  \n品  \n2.ALL DIMENSIONS IN MILLIMETRES AND LEVELS IN METRES  \n2.DURING EXCAVATION CARE MUST BE TAKEN TO ENSURE THAT SERVICES ARENOT DISTURBED OR DAMAGED.ADEQUATE SUPPORT IS TO BE PROVIDED TO ALLEXPOSED SERVICES.IT IS THE CONTRACTORS RESPONSIBILITY TO LOCATE ANDPROTECT ANY SERVICES AND ANY DAMAGE IS TO BE REPAIRED AT THECONTRACTORS OWN EXPENSE.THE RAINWATER DOWN PIPE IS TO BE TAKEN TOA NEW SOAKAWAY.  \n3.AN ALLOWABLE GROUND BEARING PRESSURE OF 100KN/m²REQUIRED ON SITE TO BECHECKED PRIOR TO CONSTRUCTION.ALL FOUNDATION FORMATIONS TO BE THE APPROVALOF LOCAL AUTHORITY BUILDING INSPECTORS-IF IN DOUBT REFER BACK.  \n150mm THICK RC35 GRADE SLAB  \nCONTRACTOR IS TO  \nREINFORCED WITH ONE LAYER OF  \nENSURE THE EXISTING  \nA393 MESH FABRIC TOP(35mm  \nWALL IS NOT UNDERMINED  \nDURING WORKS.IF IN  \nCOVER)ON 1200 GAUGE D.P.M ON  \n4.FOUNDATIONS DEPTH TO BE IN ACCORDANCE WITH NHBC PRACTICE NOTE 3,'BUILDINGNEAR TREES'WHERE EXISTING TREES ARE RETAINED AND/OR NEW PLANTING SCHEMESDICTATE.  \nDOUBT REFER BACK TO  \nA MINIMUM 150mm WELL COMPACTED  \n3.EXCAVATION AND THE STORAGE OF EXCAVATED MATERIAL IS TO BE CARRIEDOUT IN SUCH A WAY AS TO MINIMISE DAMAGE TO ADJACENT GROUND.  \n300  \nENGINEER FOR APPROVAL  \nHARDCORE BLINDED WITH SAND  \n△D  \nD/  \n4.ALL EXCAVATIONS FOR UNDERPINNING LEGS ARE TO BE TAKEN DOWNVERTICALLY AND KEPT CLEAN AND FREE OF WATER.ALL JOINTS AGAINST LEGSALREADY CONSTRUCTED TO BE THROUGHLY CLEANED.DRAIN PIPES ARE TO BEINSTALLED AT THE LEVEL OF ANY SOFT MATERIAL.  \n600mm WIDE FOUNDATIONS  \n5.CONCRETE FOR UNREINFORCED FOUNDATIONS DESIGNATED MIX GEN 3(20N)TO B.S.5328.  \n300mm WIDE x  \nFOUNDED A MINIMUM 1000mm  \n300mm THICK EDGE  \n600  \nBELOW GROUND LEVEL.GEN 3  \nSLAB THICKENING  \nGRADE CONCRETE  \n6.CONCRETE FOR REINFORCED SLAB TO BE DESIGNATED MIX GRADE RC35 TO B.S.5328:  \n3po  \nPART 2:1991  \n5.EXCAVATION FOR ANY UNDERPINNING LEG IS NOT TO BE COMMENCED UNTILAT LEAST 1 DAY AFTER FINAL PINNING OF AN ADJACENT LEG.  \n300  \n7.MESH FABRIC TO B.S.4483 AND TO HAVE MIN 400mm LAPS  \n# TYPICAL ELEVATION ON UNDERPINNING SECTIONS\n\n6.MAXIMUM LENGTH OF UNDERPIINING TO BE 1000mm.UNDERPIINING TO BECARRIED OUT IN SEQUENCE AS SHOWN ON PLAN.  \n8.MESH TO BE ADEQUATELY SUPPORTED DURING CASTING OF CONCRETE AND TO HAVEMIN 35mm COVER TO SLAB.  \n300  \n300mm WIDE x 300mm THICK  \nSLAB THICKENING BELOW  \nTEMPORARY SHORING TO  \n7.UNDERPINNING IS TO BE CARRIED OUT IN MASS CONCRETE AS SHOWN TO ADEPTH OF 900mm BELOW GROUND LEVEL.  \nE△  \nINTERNAL BLOCK WALLS  \n9.ALL BLOCKWORK BELOW DPC LEVEL 7N UNLESS NOTED OTHERWISE &IN MORTARTYPE(i)TO B.S.5628(1:3 CEMENT:SAND).  \n△E  \nEXG WALLS TO BE ——  \nDETAILED BY PRINCIPLE  \nCONTRACTOR  \n8.UNDERPINNING IS TO BE CARRIED OUT IN SEQUENCE NOT EXCEEDING1000mm IN LENGTH.THE CONSTRUCTION OF AN UNDERPINNING LEG SHALL BECOMMENCED IMMEDIATELY AFTER EXCAVATION OF THE LEG.  \n5  \n10.STRUCTURAL STEELWORK TO BE IN ACCORDANCE WITH NATIONAL STRUCTURALSTEELWORK SPECIFICATION FOR BUILDING CONSTRUCTION (LATEST EDITION).  \n21  \n4」  \n3  \n2  \n3  \n1  \n4  \n5  \n11.STRUCTURAL STEELWORK GRADE S355 AND PAINTED WITH ZINC PHOSPHATE PRIMERTO B.S.2569.  \n9.ALL SOIL AND LOOSE MATERIAL IS TO BE REMOVED FROM THE UNDERSIDEOF THE EXISTING FOUNDATIONS BEFORE UNDERPINNING COMMENCES.  \n6  \n150mm THICK RC35 GRADE SLAB  \n12.BOLTS TO BE GRADE 8.8 UNLESS STATED OTHERWISE.  \nREINFORCED WITH ONE LAYER OF  \n10.UNDERPINNING IS TO BE GENERALLY CARRIED DOWN TO A DEPTH OF  \n8  \nA393 MESH FABRIC TOP(35mm  \n900mm BELOW EXG GROUND LEVEL.  \n13.CONNECTIONS NOT SHOWN ON SKETCHES,CALCULATIONS OR DRAWINGS TO BEDESIGNED AND DETAILED BY STEELWORK FABRICATOR.  \nCOVER)ON 1200 GAUGE D.P.M ON  \n11.THE FIRST STAGE OF UNDERPINNING IS TO BE IN MASS CONCRETE OF 1:  \nA MINIMUM 150mm WELL COMPACTED  \n1.5:3 MIX PROPORTIONS(ORDINARY PORTLAND CEMENT:FINE AGGREGATE:150mm THICK RC35 GRADE-COARSE AGGREGATE).ALL C","cbCaiuYHmos3lEZA","https://ap.wps.com/l/cbCaiuYHmos3lEZA","pdf",443342,"English","# Underpinning excavation and site preparation\n## Dimensions, tolerances, and service protection\n## Concrete mixes, reinforcement, and blinding\n## Sequencing, maximum lengths, and approvals\n## Steelwork, welding, and lateral restraint","[{\"question\":\"What excavation methods are permitted for the underpinning works?\",\"answer\":\"All excavation must be either hand dug or carried out by light mechanical excavator as approved by the engineer.\"},{\"question\":\"What concrete mixes and reinforcement requirements are specified?\",\"answer\":\"Unreinforced foundations use designated mix GEN 3(20N) and reinforced slabs use RC35 grade concrete to the referenced standards. Mesh fabric must meet specified lap and cover requirements, and concrete for pinning uses semi-dry rammed hardcore blinding with sand.\"},{\"question\":\"How should underpinning legs be sequenced and limited in length?\",\"answer\":\"Underpinning must be carried out in sequence as shown on plan, with maximum underpinning length of 1000mm and legs completed following the stated timing between adjacent stages.\"}]","TYPICAL ELEVATION ON UNDERPINNING SECTIONS - engineering notes for excavation and concrete requirements | PDF"]