THOR:
PHS (pneumo-hydraulic system) pile-driving hammer
Basic technology comparison and project description.
Existing solutions
A number of construction sites that use piles in the building foundation as a main loadbearing structure increases annually in civilian and industrial sectors, worldwide. That requires a big number of pile-driving hammers of three different types:
1st group
cylinder and rod diesel hammers
Oldest type, but still popular. Used to knock piles.
Oldest type, but still popular. Used to knock piles.
2nd group
hydraulic pile-driving hammers
produced for several decades without any remarkable improvements in the construction.
produced for several decades without any remarkable improvements in the construction.
3rd group
pile-squeezing machines
All of these types are used in modern construction processes and has advantages and disadvantages comparing to each other.
Cylinder and rod diesel hammers
Advantages:
Disadvantages:
- Extremely cheap (5−6 times cheaper than hydraulic hammers),
- can knock piles heavier than anvil block of the hammer; but that the only advantages.
Disadvantages:
- it has low performance in soft soil (hard to launch),
- it's impossible to change knocking power and energy,
- It can't be used next to existing buildings due to soil vibrations, diesel smoke, etc. (diesel air-fuel mixture in the chamber can't be regulated), so this type is forbidden in populated areas of the cities.
Scheme 1
1 — catcher
2 — load block
3 — Body of the cylinder
4 — sealing rings
5 — air pipe
6 — fuel pump
7 — anvil
8 — cushion block
9 — pile
2 — load block
3 — Body of the cylinder
4 — sealing rings
5 — air pipe
6 — fuel pump
7 — anvil
8 — cushion block
9 — pile
Hydraulic pile-driving hammers
Scheme 2
1 — low/high pressure accumulators
2 — hydraulic cylinder
3 — body
4 — load block
5 — cushion block
6 — pile
2 — hydraulic cylinder
3 — body
4 — load block
5 — cushion block
6 — pile
Advantages:
Disadvantages:
- Stabile work on any soil,
- number of knocks can be changed
Disadvantages:
- can only knock piles lighter than diesel hammers (with equal weight of anvil block),
- Knocking power can't be changed in the process (piles go slower with increasing of depth/soil resistance), even increasing number of knocks, single knock power decreses,
- it's 5−6 times more expensive than diesel hammers,
- Also cannot be used in populated areas near buildings due to created soil vibration.
Squeezing pile-driving machines
Advantages:
Disadvantages:
- can be used near existing buildings in populated area
Disadvantages:
- such machines are huge (for example, STARKE machine has max pressure of 320 tons while its own weight is 120 tons and 320 tons with load block in operational mode),
- it requires a lot of raw materials to produce and extremely expensive
- complicated and expensive logistics (limit of max.20 tons on the roads),
- complicated and long time assembly on the site, requires long time to move.
- max power is limited by its own weight.
Scheme 3
1 — pile
2 — crane
3 — squeezing hydro-cylinders
4 — load block
5 — machine body
2 — crane
3 — squeezing hydro-cylinders
4 — load block
5 — machine body
Market conditions
- The main disadvantage of all these machines - mostly it can't be used in a big cities in hotspot (infill) construction. Diesel and hydraulic pile-driving hammers creates seismic vibrations, while squeezing machines has limitations by its size and weight and complicated delivery to the site (STARKE 320 – length 12m, width almost 10m, height 7m, weigh 120 tons).
- So currently hotspot (infill) construction use a bored cast-in-place pile technology, and building foundation cost 3 times more than knocked piles foundation. And it takes 1,5-2 month longer to bore, and its impossible to calculate exact load capacity of such piles. Also drilling/boring machines cost a lot. All that greatly increase construction cost and time.
- All existing types of the machines are being produced without remarkable improvement for decades. At the moment 60% of all hammers are produced under 4 major brands – German MENCK, British BSP, Finland JUNTTAN, Holland IHC and only 40% belongs to other brands.
- Total market capacity is about 50 billion USD (but we expect real capacity at least two times more considering growing markets of China, India, etc., that has no proved statistics).
The most authority magazine, that is focused on pile technologies, - Pile Buck (USA), there are total 14 companies in the world producing more than 220 models of pile-driving hammers with knocking mass from 1 to 180 tons. And there is no existing new technology in this market. Its impossible to improve the process without principally new scheme of the machine and without additional energy source.
Our solution: "THOR" PHS hammer
Scheme 4
1 — body
2 — Load block catching sytem
3 — load block
4 — block loading system
5 — accelerating chamber
6 — energy convertor
7 — pile destruction protector
8 — pile
2 — Load block catching sytem
3 — load block
4 — block loading system
5 — accelerating chamber
6 — energy convertor
7 — pile destruction protector
8 — pile
- THOR is an absolutely new device based on a different concept of operation, that uses additional energy source aside of hydraulic power, allowing to combine knocking and squeezing technologies, increase knocking power and number of knocks in the process while keeping a single knock energy at its maximum.
- We can also decrease a single knock energy if required. On the opposite, it will increase number of knock even more. THOR can regulate (increase or decrease) maximum power of pressure on the pile in the process.
- THOR PHS hammer presents a specter of innovations that are unavailable to any of an existing technologies.
THOR PHS hammer
PHS system (*conventional name) is uniting an advantages of all 3 existing groups of hammers, without any disadvantages:
THOR can operate in 3 modes:
- Mode 1 - knocking,
- Mode 2 - knocking + squeezing,
- Mode 3 - squeezing only
THOR can stably operate on any soil,
THOR is 5-6 times more powerful and effective comparing to any other machine with equal weight of load block - this number is lowered. Calculated effect is even better in theory
In the process of knocking and squeezing of pile THOR can increase its power to prevent slowing (due to the growing pressure resistance of the soil) of pile speed
THOR can change (in a wide range) its knocking frequency, energy of single knock, and power of pressure on the pile
THOR reaches a squeezing power few times more than own weight of the pile
Cost of THOR PHS hammer is nearly equal to the standard hydraulic hammer (comparing the same weight of the load block)
THOR can operate with much bigger weight of the pile than a similar size of hydraulic hammer. So we greatly decrease a model range, required to cover all needs of the construction companies.
Comparing of characteristics of the standard hammer model HR50 and THOR PHS hammer (in Table 1)
THOR characteristics are taken as average from the calculated maximum. In theory it will be even higher.
THOR characteristics are taken as average from the calculated maximum. In theory it will be even higher.
Table 1
THOR PHS operation time (*required for processing of one pile) is several times faster than any existing solution.
Resume
Manufacturers of diesel and hydraulic systems has protected their market by a number of patents, that prevents new players appearing on the global market . Still nothing has changed in principle scheme of such hammers in past decades. Its impossible to improve an efficiency of existing solutions. Different manufacturers shows absolutely similar parameters of their machines, while some of them tries to cheat, using some marketing tools, real characteristics are limited by physical principles (if weight of load block is equal, then energy of single strike and number of knocks will be equal too).
THOR PHS system – presents an absolutely new scheme of work based on different physical principles, offering a pack of innovations unavailable to any existing solutions. We created it 'from scratch'. When THOR appears in construction market it would result in extinction of hydraulic and diesel hammers, squeezing machines drilling/boring cast-in-place pile machines in relatively short period of time. Only diesel hammers may keep some market share due to its extremely low cost and construction simplicity.
Product portfolio and MVP
Our technology allows us to produce a various types of the machines. In 2011 we built an MVP sample of horizontal pile-driver/communication piping machine as a proof of concept. It has completely confirmed theory and calculations, and was used at several construction sites.
This video presents a process of communication folder insertion under the road pavement in a hard soil, in knock-and-squeeze combined mode: pipe goes with constant high speed, without slowing after each knock, under the force of energy converter.
Our horizontal solution being technically similar to the THOR hammer has many advantages to existing horizontal boring or knocking machines:
1
It's universal and can drive a various types communication folders/pipes of different sizes and materials (steel, armored concrete, ceramic, plastic).
2
Has high precision of insertion.
3
High speed of operation/insertion.
4
Low cost
5
Level of underground waters doesn't matter (its hermetic).
6
No air comsumption.
Aside of large pile-driving hammers we can build a small, rig (excavating attachment) hammers/drillers
that can be used on various tractors and excavators:
It replaces a standard mobile equipment for drilling of frozen soil, asphalt, old constructions and foundations.
Operates much faster (the same reason: conventional rigs uses a force of hydraulic liquid only, so its knocking energy is very small), while we use an energy converter which allows to increase knocking energy many times)
Mikhail Rogov
Managing Partner