![\"Unit](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/07\/a2c55c047312343098f6e2e34274fd06.jpg\")
Hello, everyone.<\/p>\nHello, everyone.<\/p>\n
This is Enta.<\/p>\n
A while back, a young field supervisor from another company asked me, \u201cDo you pay attention to the soil conditions when drilling holes for ground anchors?\u201d<\/p>\n
(No, seriously, you should really care about this, lol)<\/p>\n
If you underestimate the soil conditions when estimating costs, you'll be the one crying about it later.<\/p>\n
![\"Drilling](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2023\/04\/2023-01-12-10.16.14-1.jpg\")
<\/p>\n
But that's beside the point.<\/p>\n
The unit cost for drilling in ground anchor construction can literally \u201cmore than double\u201d depending on the soil conditions.<\/p>\n
A lot of construction companies just kind of throw out a quote, thinking, \u201cHonestly, this is probably about right,\u201d don\u2019t they?<\/p>\n
I know exactly how you feel!<\/p>\n
But I think you know it\u2019s definitely better to review the design specifications carefully to confirm the stiffness before submitting a quote.<\/p>\n
In this session, we\u2019ll explain how to prepare a cost estimate while reviewing the 2026 cost estimation materials.<\/p>\n
![\"Illustrated](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/07\/4e3098cef3673d731074c62ea610a0b2.jpg\")
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First and foremost, cost estimation for ground anchor work is based on a package system.<\/p>\n
The term \u201cpackage\u201d refers to a system in which a series of tasks\u2014such as drilling, grout injection, steel fabrication and assembly, tensioning and anchoring, and head finishing\u2014are each billed as separate line items.<\/p>\n
According to the Ministry of Land, Infrastructure, Transport and Tourism\u2019s construction package-based cost estimation standards, when drilling for ground anchor work, \u201ccosts shall be calculated separately for each soil type.\u201d<\/p>\n
In other words, when there are mixed soil types at a site, the basic principle is to calculate quantities separately for each soil type.<\/p>\n
\"Just classifying everything as cohesive soil\" is a no-go.<\/p>\n
(I'll be in for a world of trouble later, lol)<\/p>\n
Incidentally, in this year\u2019s cost estimation guidelines (2026 Cost Estimation), as in the past, the following work items are listed separately in addition to drilling costs.<\/p>\n
\u2013 Drilling machine relocation service: 56,040 yen per visit
\n\u2013 Grout Injection Worker: 65,840 yen per cubic meter
\n\u2013 Steel processing, assembly, insertion, tensioning, anchoring, and head treatment: Vary depending on standards, load ratings, and corrosion protection specifications<\/p>\n
It is only when all these factors are taken into account that the \u201cunit price per anchor\u201d is determined.<\/p>\n
That\u2019s exactly why it\u2019s pointless to judge whether something is \u201ccheap\u201d or \u201cexpensive\u201d based solely on the drilling costs.<\/p>\n
![\"Comparison](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/07\/34181c8e10919594d584093c7e7ced84.jpg\")
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Soil classifications for ground anchor drilling are broadly divided into five categories.<\/p>\n
1. Cohesive soils and sandy soils
\n2. Gravelly Soil
\n3. Soil with a mixture of good and bad stones
\n4. Soft Rock
\n5. Hard Rock<\/p>\n
The unit price for drilling varies significantly across these five categories.<\/p>\n
As for why things change...<\/p>\n
Basically, it\u2019s because the \u201ccutting speed (drilling efficiency)\u201d varies greatly depending on the soil type.<\/p>\n
In cohesive soil, the boring machine moves along smoothly, but when it hits hard rock, it takes several times as long to drill to the same depth.<\/p>\n
The longer it takes, the higher the labor and equipment costs will be.<\/p>\n
It's as simple as that: the unit price goes up.<\/p>\n
<\/p>\n
As of March 2017, the unit prices listed on this blog (skid-type, double-pipe system, borehole diameter 90 mm) were as follows.<\/p>\n
Soil Classification: Unit Prices as of March 2017 (yen\/m)<\/strong><\/p>\n Clay and sandy soils ... 6,453<\/strong><\/p>\n Gravelly Soil... 10,610 <\/strong><\/p>\n Soil mixed with stones... 16,230<\/strong><\/p>\n Soft Rock... 13,080<\/strong><\/p>\n Hard Rock... 17,240<\/strong><\/p>\n When comparing cohesive soil to hard rock, there is a difference of approximately 2.67 times.<\/p>\n (If you estimate this by thinking, \u201cIt\u2019s pretty much the same, right?\u201d, you\u2019re in big trouble lol)<\/p>\n Please note that the unit price shown \ud83d\udc46 is for reference only and reflects the price as of March 2017.<\/p>\n Since the current unit prices are revised annually, please be sure to always check the most up-to-date civil engineering construction unit prices. \ud83d\udc47<\/p>\n These are the drilling costs from the 2026 cost estimate documents that Enta has on hand.<\/p>\n The unit prices (yen\/m) by soil type for a borehole diameter of 90 mm are as follows.<\/p>\n Soil Classification Unit Price (yen\/m)<\/strong><\/p>\n Clay and sandy soil... 9,387<\/strong><\/p>\n Gravelly soil... 15,450<\/strong><\/p>\n Soil mixed with stones... 23,680<\/strong><\/p>\n Soft Rock... 19,070<\/strong><\/p>\n Hard Rock... 25,120<\/strong><\/p>\n Compared to 2017, prices have risen across all categories.<\/p>\n Looking at clay and sandy soils, the price has gone from 6,453 yen to 9,387 yen, which is about 1.45 times as much.<\/p>\n Although the unit price increases as the hole diameter gets larger, we are comparing them based on a diameter of 90 mm in this case.<\/p>\n The price per unit for \u03c6115mm, \u03c6135mm, and \u03c6146mm is listed in the documentation; however, since the specifications vary depending on the diameter, please check the design carefully.<\/p>\n Also, please note that this unit price applies solely to the \u201cdrilling cost.\u201d<\/p>\n The costs for the boring machine relocation, grout injection, and steel fabrication and assembly mentioned earlier are billed separately.<\/p>\n To be honest, there are quite a few documents that try to determine the unit price for the entire anchoring project based solely on drilling costs, and it\u2019s risky to make a judgment based on that lol.<\/p>\n (Which means it costs 56,040 yen just to move it once, lol.)<\/p>\n Make sure your quote includes all the items specified in the design!<\/p>\n <\/p>\n \ud83d\udc47\ud83d\udc47\ud83d\udc472026 Drilling Unit Price<\/p>\n There are three points in particular that you should pay close attention to when preparing estimates and cost calculations:<\/p>\n \u2460 Be sure to record the number of times the drilling machine is moved<\/strong><\/p>\n According to this document (2026 Aichi Prefecture Cost Estimates), the cost for relocation work is 56,040 yen per instance.<\/p>\n The total cost varies significantly depending on how many anchors are installed and how many times they are relocated on site.<\/p>\n Please carefully check the site layout and anchor placement.<\/p>\n This is a basic concept, but let's say, for example, there are three levels of scaffolding. You lift it up to the first level of the on-site scaffolding. That counts as one lift. Next, we'll lower it onto the ground. This isn't the third time, though...<\/p>\n Therefore, if there are three levels, the relocation work will take place twice.<\/p>\n \u2461 Carefully calculate the amount of grout to be injected (the terms of the estimate are important)<\/strong><\/p>\n The cost for grout injection work is 65,840 yen per cubic meter (based on the 2026 Aichi Prefecture cost estimate).<\/p>\n The formula for calculating the grout injection volume is based on the borehole diameter and length; in the case of quantity takeoff, this is specified in the design quantities, but<\/p>\n Since experience is factored into the estimate, please make sure to calculate it carefully lol<\/p>\n \u2462 Steel fabrication and assembly costs vary significantly depending on the load classification, corrosion protection specifications, and whether assembly is performed in a factory or on-site.<\/strong><\/p>\n According to the 2026 Aichi Prefecture Cost Estimation Guidelines, the unit price is 40,860 yen per piece for double corrosion protection, PC steel strands, on-site assembly, lengths of 10 meters or less, and f < 400 kN, provided that end treatment is included.<\/p>\n Even with the same double anti-corrosion coating, the price drops to 18,570 yen per unit when assembled at the factory.<\/p>\n (Even though there\u2019s a difference of about 2.2 times, factory processing is still cheaper because of the on-site assembly costs.)<\/p>\n (Temporary)<\/td>\n In particular, I\u2019d like companies that rely solely on subcontracting to make sure they adjust their unit prices for each item.<\/p>\n You must not use a \"lump-sum\" contracting method!<\/p>\n Sandy soil \u25cb\u25cb m; unit price \u00d7 design length =<\/p>\n Soft rock \u25cb\u25cb m; unit price \u00d7 design length =<\/p>\n Please give me a quote based on that.<\/p>\n As I\u2019ve mentioned in previous articles, this is an issue that remains unresolved to this day.<\/p>\n The unit price has been rising slightly every year.<\/p>\n According to documents from the Ministry of Land, Infrastructure, Transport and Tourism, the Standard Unit Price Table for the Construction Package Cost Estimation Method is updated every fiscal year, and<\/p>\n We have updated the base dates for machinery, labor, and material unit costs, as well as market unit prices, to reflect changes in prices.<\/p>\n Unit prices are rising.<\/p>\n But when it comes to the reality of the bidding process, even if unit prices rise, if the volume of work decreases, companies will compete to lower their prices.<\/p>\n The trend of going after new business\u2014even at the expense of social insurance premiums and company profits\u2014remains unchanged to this day.<\/p>\n The real question is, how many companies are actually making a profit while paying their social insurance and taxes in full?<\/p>\n While the government is raising labor rates and urging companies to \u201cimprove working conditions,\u201d the reality is that competition is driving down rates at the front-line level.<\/p>\n Gain a thorough understanding of the cost estimation process and prepare estimates using accurate unit prices.<\/p>\n I believe that is the only way to survive in the long run.<\/p>\n The latest drilling rates are updated every April and July.<\/p>\n Be sure to check the latest edition of the \u201cCivil Engineering Construction Unit Prices\u201d or the contracting agency\u2019s cost estimation standards every year.<\/p>\n <\/p>\n By the way, I\u2019m thinking of using AI to create a calculation tool specifically for slopes that anyone can use, but I\u2019m wondering if there\u2019s actually a demand for it\u2014so for now, I\u2019m just steadily working on other things lol.<\/p>\n Personally, I\u2019d like people who\u2019ve never done cost estimation and have no idea how much money the general contractor gets from the government to use this.<\/p>\n I'm thinking that if I do that, I might start to get a better sense of unit prices, even if just a little.<\/p>\n <\/p>\n See you later.<\/p>\n Cost Estimation Data for Packers | Unit Price Information<\/a><\/p><\/blockquote>\nCurrent Drilling Unit Prices Based on 2026 Cost Estimation Data<\/h2>\n
![\"Ground](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/07\/beb1fedf417187c29c0f3096ecc56b6c.jpg\")
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\n Drill Hole Diameter<\/td>\n Clay and Sandy Soil<\/td>\n Gravelly Soil<\/td>\n Soil mixed with stones and pebbles<\/td>\n Soft rock<\/td>\n Hard Rock<\/td>\n<\/tr>\n \n 90<\/td>\n 9,387<\/td>\n 15,450<\/td>\n 23,680<\/td>\n 19,070<\/td>\n 25,120<\/td>\n<\/tr>\n \n 115<\/td>\n 13,790<\/td>\n 19,100<\/td>\n 28,800<\/td>\n 23,150<\/td>\n 30,010<\/td>\n<\/tr>\n \n 135<\/td>\n 16,940<\/td>\n 23,220<\/td>\n 33,350<\/td>\n 28,300<\/td>\n 36,130<\/td>\n<\/tr>\n \n 146<\/td>\n 20,340<\/td>\n 28,190<\/td>\n 40,070<\/td>\n 34,360<\/td>\n 47,410<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Points to Keep in Mind When Preparing Estimates and Cost Calculations<\/h2>\n
![\"Points](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2026\/07\/0625e331a26d83cfaf7a0bebb5f8d2d1.jpg\")
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\nLower it to the second level. That makes two times.<\/p>\n\n\n
\n Anchor Steel Processing, Assembly, Insertion, Tensioning, Anchoring, and Head Finishing (Anchors)<\/td>\n <\/td>\n <\/td>\n<\/tr>\n \n <\/td>\n Types<\/td>\n Length<\/td>\n Load<\/td>\n Whether or Not the Head Is Processed<\/td>\n Unit Price<\/td>\n<\/tr>\n \n Double Corrosion Protection<\/td>\n PC steel strand<\/td>\n Within 10 meters<\/td>\n f < 400 kN<\/td>\n Available<\/td>\n 40,860<\/td>\n<\/tr>\n \n On-site Assembly<\/td>\n <\/td>\n None<\/td>\n 37,040<\/td>\n<\/tr>\n \n 400 \u2264 f < 1300 kN<\/td>\n Available<\/td>\n 44,560<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 40,750<\/td>\n<\/tr>\n \n 130 kN \u2264 f < 2000 kN<\/td>\n Available<\/td>\n 56,960<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 53,140<\/td>\n<\/tr>\n \n More than 10 meters<\/td>\n f < 400 kN<\/td>\n Available<\/td>\n 42,370<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 38,550<\/td>\n<\/tr>\n \n 400 \u2264 f < 1300 kN<\/td>\n Available<\/td>\n 46,080<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 42,260<\/td>\n<\/tr>\n \n 130 kN \u2264 f < 2000 kN<\/td>\n Available<\/td>\n 58,470<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 54,650<\/td>\n<\/tr>\n \n PC Steel Strand (Factory-Assembled)<\/td>\n <\/td>\n f < 400 kN<\/td>\n Available<\/td>\n 18,570<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 14,750<\/td>\n<\/tr>\n \n 400 \u2264 f < 1300 kN<\/td>\n Available<\/td>\n 21,110<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 17,290<\/td>\n<\/tr>\n \n 130 kN \u2264 f < 2000 kN<\/td>\n Available<\/td>\n 30,020<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 26,200<\/td>\n<\/tr>\n \n Basic Corrosion Protection<\/p>\n PC steel strand<\/td>\n Within 10 meters<\/td>\n f < 400 kN<\/td>\n Available<\/td>\n 28,070<\/td>\n<\/tr>\n \n On-site Assembly<\/td>\n <\/td>\n None<\/td>\n 24,250<\/td>\n<\/tr>\n \n 400 \u2264 f < 1300 kN<\/td>\n Available<\/td>\n 37,590<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 33,770<\/td>\n<\/tr>\n \n 130 kN \u2264 f < 2000 kN<\/td>\n Available<\/td>\n 56,960<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 53,140<\/td>\n<\/tr>\n \n More than 10 meters<\/td>\n f < 400 kN<\/td>\n Available<\/td>\n 29,580<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 25,760<\/td>\n<\/tr>\n \n 400 \u2264 f < 1300 kN<\/td>\n Available<\/td>\n 39,100<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 35,280<\/td>\n<\/tr>\n \n 130 kN \u2264 f < 2000 kN<\/td>\n Available<\/td>\n 58,470<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 54,650<\/td>\n<\/tr>\n \n PC Steel Strand (Factory-Assembled)<\/td>\n <\/td>\n f < 400 kN<\/td>\n Available<\/td>\n 17,470<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 13,650<\/td>\n<\/tr>\n \n 400 \u2264 f < 1300 kN<\/td>\n Available<\/td>\n 20,010<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 16,200<\/td>\n<\/tr>\n \n 130 kN \u2264 f < 2000 kN<\/td>\n Available<\/td>\n 28,920<\/td>\n<\/tr>\n \n <\/td>\n None<\/td>\n 25,100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n ![\"Drilling](\"https:\/\/norimen.net\/wordpress\/wp-content\/uploads\/2024\/02\/2024-02-28-10.25.51.jpg\")
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