{"id":4146,"date":"2026-09-08T07:34:00","date_gmt":"2026-09-07T23:34:00","guid":{"rendered":"https:\/\/ksnrsolar.com\/geotechnical-investigation-solar\/"},"modified":"2026-09-08T07:34:00","modified_gmt":"2026-09-07T23:34:00","slug":"geotechnical-investigation-solar","status":"publish","type":"post","link":"https:\/\/ksnrsolar.com\/de\/geotechnical-investigation-solar\/","title":{"rendered":"Geotechnical Investigation for Solar Projects"},"content":{"rendered":"<style>\n.el-sec{background:#fff;border-radius:8px;box-shadow:0 1px 4px rgba(20,40,80,.08);padding:34px 42px;margin:0 auto 22px;max-width:1020px;box-sizing:border-box}\n.el-h{color:#1E293B;margin:0 0 14px}\nh2.el-h{font-size:26px;text-align:center;border-left:none;padding-left:0;line-height:1.3;margin-bottom:22px}\nh2.el-h::after{content:'';display:block;width:60px;height:3px;background:#F9960E;margin:12px auto 0;border-radius:2px}\nh3.el-h{font-size:19px}\n.el-hero{padding:0;overflow:hidden}\n.el-overlay{padding:48px 38px;text-align:center}\n.el-overlay .el-check{display:inline-block;text-align:left}\n.el-row{display:flex;gap:16px;align-items:stretch;flex-wrap:wrap}\n.el-col{background:#F0F5FA;border:1px solid #D1D5DB;border-radius:6px;padding:16px 18px;box-sizing:border-box}\n.el-col>.el-sec{margin:0;height:100%;box-shadow:none;background:#fff}\n.el-col>.el-sec .el-btn{white-space:nowrap}\n.el-btn{display:inline-block;background:#0097B4;color:#fff !important;padding:10px 26px;border-radius:5px;text-decoration:none;font-weight:600;font-size:15px}\n.el-check{list-style:none;margin:10px 0;padding:0}\n.el-check li{padding:5px 0 5px 26px;position:relative}\n.el-check li::before{content:'\u2713';position:absolute;left:2px;color:#1E8A5F;font-weight:700}\n.el-box{background:#F0F5FA;border:1px solid #D1D5DB;border-radius:6px;padding:16px 18px;margin:8px 0}\n.el-box-icon{font-size:24px;margin-bottom:6px}\n.el-box h4{color:#1E293B;margin:0 0 6px;font-size:16px}\n.el-box p{font-size:14px;color:#334155;margin:0}\n.el-acc details{border:1px solid #D1D5DB;border-radius:6px;margin:0 0 10px;background:#F9FAFB}\n.el-acc summary{padding:13px 18px;cursor:pointer;font-weight:600;color:#1E293B}\n.acc-body{padding:4px 18px 14px;font-size:14.5px;color:#334155}\n.el-cta{text-align:center}\n.el-cta .el-h{color:#fff;border-left:none;padding-left:0}\n.el-cta .el-btn{background:#1E293B}.el-cta .el-text{color:#fff}.el-cta .el-text p{color:rgba(255,255,255,.92)}\n.el-sec table{width:100%;border-collapse:collapse;margin:12px 0;font-size:14.5px}\n.el-sec th,.el-sec td{border:1px solid #D1D5DB;padding:9px 12px;text-align:left;vertical-align:top}\n.el-sec th{background:#F0F5FA;color:#1E293B}\n.el-sec tr:nth-child(even) td{background:#F9FAFB}\n.el-text p{margin:0 0 10px}\n.el-text ul{margin:0 0 10px 22px}\n.el-text a{color:#0097B4}\n.el-band{background:#F0F5FA;border-radius:8px;max-width:1020px;margin:0 auto 22px;padding:18px 30px;font-size:15px;box-sizing:border-box}\n.el-band p{margin:0}\n.el-media{display:flex;gap:30px;align-items:center}\n.el-media.rev{flex-direction:row-reverse}\n.el-media-txt{flex:1.15;min-width:0}\n.el-media-img{flex:1;min-width:0}\n.el-media-img img{width:100%;height:auto;display:block;border-radius:8px;box-shadow:0 2px 10px rgba(20,40,80,.14)}\nul.el-two{column-count:2;column-gap:44px}\nul.el-two li{break-inside:avoid}\n@media (max-width:767px){.el-row{flex-direction:column}.el-col{flex:none !important;max-width:100% !important}.el-sec{padding:22px 18px}.el-overlay{padding:32px 20px}.el-media,.el-media.rev{flex-direction:column;align-items:stretch}ul.el-two{column-count:1}.el-band{padding:14px 18px}}\n.el-btn:hover{background:#F9960E}\n<\/style>\n<section class=\"el-sec el-hero\" style=\"background-image:url(\/wp-content\/uploads\/2026\/09\/ps-sub-ps-06-3-a-1.jpg);background-size:cover;background-position:center;\">\n<div class=\"el-overlay\" style=\"background:rgba(255,255,255,0.84);\">\n<h2 class=\"el-h\">Geotechnical Investigation for Solar Projects<\/h2>\n<div class=\"el-text\">\n<p>The geotechnical investigation is the smallest line item in a solar project and the one that determines whether the foundation budget survives construction. It is also routinely under-scoped, because the cost of additional boreholes is visible now and the cost of unexpected ground conditions appears later, in someone else&#8217;s budget.<\/p>\n<p>A well-scoped investigation does three things: it classifies the soils across the site rather than at one point, it tests corrosivity so the coating class is chosen rather than assumed, and it produces findings that map directly onto foundation design decisions instead of a general description of the ground.<\/p>\n<\/div>\n<p><a class=\"el-btn\" href=\"\/de\/contact-us\/#contactpopupform\">Request a Project Quote<\/a><\/div>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Why This Is Difficult<\/h2>\n<div class=\"el-text\">\n<p>Under-scoped investigations fail in predictable ways, and each failure has a well-known remedy that costs far less than the consequence.<\/p>\n<\/div>\n<ul class=\"el-check\">\n<li>A single central borehole on a 200 hectare site describes one point and leaves the rest of the site as an assumption<\/li>\n<li>Soil corrosivity is frequently omitted from solar investigations, and it drives both pile coating class and corrosion allowance<\/li>\n<li>Foundation quantities are priced from the investigation, so an over-general report produces either over-design or a variation claim<\/li>\n<li>Refusal, groundwater and rock head depth are the three conditions that most often stop a piling programme, and all three are measurable in advance<\/li>\n<li>Foundation design risk is usually allocated to one party by contract, so an ambiguous investigation transfers a large contingent liability<\/li>\n<li>Later stages such as access roads, inverter pads and cable trenches reuse the same data, so under-scoping the investigation constrains the whole project<\/li>\n<\/ul>\n<\/section>\n<section class=\"el-sec\">\n<div class=\"el-media rev\">\n<div class=\"el-media-txt\">\n<h3 class=\"el-h\">Engineering Requirements<\/h3>\n<div class=\"el-text\">\n<p>These are the elements a solar geotechnical investigation should contain.<\/p>\n<\/div>\n<ul class=\"el-check\">\n<li>Borehole or cone penetration test density based on site area and variability, with a defined layout rather than an arbitrary number of holes<\/li>\n<li>Soil classification and stratification to the depth of interest for foundation design, typically beyond the maximum expected embedment<\/li>\n<li>Groundwater level and its seasonal variation, since it affects both capacity and foundation durability<\/li>\n<li>Corrosivity testing: soil resistivity, pH, sulphate and chloride content, mapped to a corrosivity class<\/li>\n<li>Rock head depth and refusal potential identified in the report rather than discovered by the piling rig<\/li>\n<li>Recommended foundation types with preliminary capacities, so the investigation produces design input rather than description<\/li>\n<\/ul>\n<\/div>\n<div class=\"el-media-img\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2026\/09\/ps-sub-ps-06-3-b-1.jpg\" alt=\"Geotechnical Investigation for Solar Projects - installation detail\" loading=\"lazy\"><\/div>\n<\/div>\n<\/section>\n<section class=\"el-band\">\n<p>Selection guidance: scope the investigation against the foundation decision it has to support. The number of boreholes matters less than whether the layout captures the variability that will actually change the foundation design.<\/p>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">How We Solve It<\/h2>\n<ul class=\"el-check\">\n<li>Investigation scoped to the site variability, with borehole density set by area and geological setting rather than by convention<\/li>\n<li>Corrosivity testing included as standard, producing a class that maps to a specific coating specification and corrosion allowance<\/li>\n<li>Findings presented as foundation design input: recommended types, preliminary capacities and refusal risk by zone<\/li>\n<li>Groundwater and rock head depths reported per zone, supporting both foundation design and civil works planning<\/li>\n<li>Results delivered in a format that supports the tender pack, so bidders price from the same data and variations are reduced<\/li>\n<li>Zone mapping across the site, so foundation types and depths can be varied where conditions change<\/li>\n<\/ul>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Beyond the Structure<\/h2>\n<ul class=\"el-check el-two\">\n<li>Data reused across the project, since access roads, inverter pads, trenches and civil works all draw on the same investigation<\/li>\n<li>An early investigation is also a procurement instrument, because it lets bidders price foundations rather than carry contingency<\/li>\n<\/ul>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Reference Benchmarks<\/h2>\n<div class=\"el-text\">\n<p>Benchmarks below are publicly documented industry reference projects of comparable type and scale, cited to illustrate engineering practice. They are not our delivery record.<\/p>\n<\/div>\n<ul class=\"el-check\">\n<li>A 200 MW site in the Middle East where corrosivity testing drove a coating class change that would otherwise have been assumed from atmospheric conditions alone.<\/li>\n<li>A 150 MW project in Spain where rock head mapping allowed foundation types to be varied by zone, avoiding a uniform deep-pile design across the whole site.<\/li>\n<li>A 120 MW project in Australia where groundwater depth reported by zone changed the corrosion allowance and reduced a contingent risk carried in the EPC price.<\/li>\n<\/ul>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Standards and Compliance<\/h2>\n<ul class=\"el-check el-two\">\n<li>ASCE 7 \/ EN 1991 \/ AS-NZS 1170 wind load cases with site-specific terrain categories<\/li>\n<li>IEC 62727 tracker structural requirements where tracking structures are in scope<\/li>\n<li>EN 1090-2 or AISC 360 fabrication and execution class documentation<\/li>\n<li>ISO 1461 hot-dip galvanizing, ISO 9223 corrosivity classification driving zinc mass<\/li>\n<li>ISO 9001:2015 quality system, ISO 14001 environmental management on request<\/li>\n<li>Third-party aeroelastic wind tunnel study available for large-format modules<\/li>\n<\/ul>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Quality Assurance<\/h2>\n<div class=\"el-text\">\n<p>Every batch ships with mill certificates, coating-thickness logs and bolt records; welds follow EN 1090 or AISC execution classes. Structure warranty runs to 10 years against a 25-30 year service design life, and spare-part packages are documented so year-12 repairs do not depend on year-1 memory.<\/p>\n<\/div>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Documentation You Receive<\/h2>\n<div class=\"el-text\">\n<p>Documentation is built for audits, not decoration: structural calculation notes stating load cases and standards used; foundation design basis mapped to your geotechnical report; material certificates for steel and fasteners; galvanizing certificates with measured coating thickness per batch; assembly drawings with torque tables; and packing documentation matched to container manifests. For financed projects we add lender-format compliance statements; for public tenders we respond to documentation schedules line by line.<\/p>\n<\/div>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Service Life and Maintenance Planning<\/h2>\n<div class=\"el-text\">\n<p>Replacement planning is part of the design: clamp geometry allows individual module swap without cutting rails, pile heads accept re-levelling after settlement, and spare-part packages are sized to your environment class and capacity. That keeps mid-life rework fast, predictable and independent of the original supplier&#8217;s product catalogue.<\/p>\n<\/div>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Cost and Commercial Considerations<\/h2>\n<ul class=\"el-check\">\n<li>Investigation cost is typically a fraction of one percent of project capex, and it is the cheapest insurance available against foundation variations<\/li>\n<li>Additional boreholes are priced individually and cheaply relative to the variation claims they prevent<\/li>\n<li>Corrosivity testing added to an existing investigation is a marginal cost, while commissioning it separately later is a new mobilisation<\/li>\n<li>An investigation delivered with preliminary capacities reduces bid contingency, which is a measurable saving in the tender result<\/li>\n<li>Lead time: 2-4 weeks for field work and reporting on a typical utility-scale site, longer where permitting or seasonal access constrains the programme<\/li>\n<\/ul>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Frequently Asked Questions<\/h2>\n<div class=\"el-acc\">\n<details>\n<summary>How many boreholes does a solar project need?<\/summary>\n<div class=\"acc-body\">Enough to describe the variability, which is a function of size and geological setting rather than a fixed number. As a rough starting point, utility-scale sites are often investigated at intervals of 100 to 200 metres across the developable area, on a defined grid rather than ad hoc placement. Where the geology changes sharply, density matters more than depth, and where the profile is uniform, fewer deeper holes can be sufficient.<\/div>\n<\/details>\n<details>\n<summary>Is corrosivity testing really necessary?<\/summary>\n<div class=\"acc-body\">Yes, and it is one of the most commonly omitted items on solar investigations. Soil resistivity, pH and chemical content determine the corrosivity class, which sets the coating specification and the corrosion allowance for buried steel. Without that data the coating is chosen by assumption, which either over-specifies and costs money or under-specifies and costs durability.<\/div>\n<\/details>\n<details>\n<summary>What should the report actually deliver?<\/summary>\n<div class=\"acc-body\">Foundation design input, not a description of the ground. The useful outputs are a zone map, recommended foundation types with preliminary capacities, refusal and rock head risk by zone, groundwater depth, and a corrosivity class with the corresponding coating recommendation. A report that describes soil layers without translating them into foundation decisions leaves the design team where it started.<\/div>\n<\/details>\n<details>\n<summary>Can we design foundations before the investigation is complete?<\/summary>\n<div class=\"acc-body\">You can develop a preliminary layout, but you should not freeze foundation design. Pricing foundations without soil data means pricing a contingency rather than a quantity, and the contingency is usually larger than the cost of the investigation. The practical sequence is to complete the investigation, then design the foundation, then tender.<\/div>\n<\/details>\n<details>\n<summary>Does the investigation help beyond foundations?<\/summary>\n<div class=\"acc-body\">Considerably. Access road design, drainage, cable trench stability, inverter and substation pad design and earthworks volumes all depend on the same soil data. One well-scoped investigation serves the whole project, which is another reason that under-scoping it early is a false economy.<\/div>\n<\/details>\n<\/div>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">Related Guides and Application Pages<\/h2>\n<div class=\"el-text\">\n<p>Continue with the pages closest to your project type.<\/p>\n<\/div>\n<ul class=\"el-two\">\n<li><a href=\"\/de\/solar-foundation-design\/\">Foundation Strategy by Project Scale<\/a> &#8211; the group overview for this scale band<\/li>\n<li><a href=\"\/de\/driven-pile-foundation-solar\/\">Driven Pile Foundations for Solar Racking Systems<\/a><\/li>\n<li><a href=\"\/de\/ground-screw-foundation-solar\/\">Ground Screw Foundations for Solar Arrays<\/a><\/li>\n<li><a href=\"\/de\/saline-alkali-solar-projects\/\">Saline-Alkali, Tidal Flat &#038; Salt-Pan Solar Projects<\/a><\/li>\n<li><a href=\"\/de\/gobi-solar-projects\/\">Gobi, Gravel &#038; Hardpan Solar Projects<\/a><\/li>\n<li><a href=\"\/de\/wetland-solar-projects\/\">Wetland, Marsh &#038; Mangrove Solar Projects<\/a><\/li>\n<\/ul>\n<\/section>\n<section class=\"el-sec\">\n<h2 class=\"el-h\">What We Need to Quote<\/h2>\n<ul class=\"el-check el-two\">\n<li>Site boundary, area and any available geological or prior investigation data<\/li>\n<li>Intended foundation type and approximate maximum embedment depth<\/li>\n<li>Access constraints and seasonal limitations for the field investigation<\/li>\n<li>Whether corrosivity and groundwater testing are required, and to which standard<\/li>\n<\/ul>\n<\/section>\n<section class=\"el-sec el-cta\" style=\"background-color:#1E293B;\">\n<h2 class=\"el-h\">Talk to a Structure Engineer<\/h2>\n<div class=\"el-text\">\n<p>Send the site boundary and the foundation concept you are working to, and we will return a suggested investigation scope and a mapping from its findings to foundation design decisions.<\/p>\n<\/div>\n<p><a class=\"el-btn\" href=\"\/de\/contact-us\/#contactpopupform\">Jetzt schnell ein Angebot anfordern<\/a><\/section>","protected":false},"excerpt":{"rendered":"<p>Geotechnical investigation solar racking guide: which configuration fits, what drives cost per watt, and which quality evidence to demand before you buy.<\/p>","protected":false},"author":1,"featured_media":3568,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[223,167],"tags":[173],"class_list":["post-4146","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-foundation-strategy-by-project-scale","category-project-scale","tag-project-scale-foundation-engineering-pv-mounting-system"],"_links":{"self":[{"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/posts\/4146","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/comments?post=4146"}],"version-history":[{"count":0,"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/posts\/4146\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/media\/3568"}],"wp:attachment":[{"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/media?parent=4146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/categories?post=4146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ksnrsolar.com\/de\/wp-json\/wp\/v2\/tags?post=4146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}