Case Study: Reducing Ground Subsidence With UHMWPE Pads

When a crane or concrete pump sinks into the ground, nobody is happy.
You lose time, rework the ground, maybe even stop the whole lifting plan.

In this case study, we’ll look at how UHMWPE pads help you cut ground subsidence on real jobsites, and why working with a high-performance engineering plastic manufacturer like Dongxing Rubber makes this more repeatable, not just lucky.

Understanding Ground Subsidence Under Crane Outriggers

On paper, the crane looks safe. You checked the load chart, rigging, radius.
Then the real world hits:

Soft backfilled soil
Hidden trenches or poor compaction
Concrete that is strong on top but weak under the surface

The outrigger feet push all that load into a very small area.
If the soil bearing capacity is lower than the pressure, the ground starts to settle. Not always fast. Sometimes it creeps a few millimeters, then more, until the crane leans and the operator feels something is “not quite right”.

So the core question is simple:

How do we spread the outrigger reaction so the ground stays inside a safe stress window?

That is exactly where UHMWPE outrigger pads come in.

How UHMWPE Outrigger Pads Reduce Ground Subsidence

Load Distribution And Soil Bearing Capacity

UHMWPE pads work like load spreaders.
You keep the same outrigger force, but you increase the contact area, so the pressure on the ground goes down.

Engineers often use a basic formula on site, even if they don’t write it down:

Required pad area ≈ Outrigger load ÷ allowable ground bearing pressure

If you oversimplify this and use too small pad area, the soil is overloaded and settlement happens.
With large UHMWPE pads, you bring the pressure closer to the design bearing capacity, which keeps subsidence under control.

Bigger pad → lower pressure
Lower pressure → less settlement
Less settlement → safer crane stablity and less drama on site

Compressive Strength And Shape Retention Of UHMWPE

Spreading the load is not enough if the pad itself crushes or deforms too much.

UHMWPE has:

High compressive strength
Very good elastic recovery
Low water absorption

So even under heavy outriggers, the pad keeps its shape and spreads the load evenly.
It “follows” small bumps in the ground but does not collapse like soft timber.

This means the effective contact area stays big during the whole lift, not just at the first minute.
Less local punching, less creep, less secret subsidence under one corner.

Durability Compared With Wood And Steel Pads

Many contractors still use timber mats or steel plates because “we always did like this”.
But they bring problems:

Wood rots, splits, absorbs water, swells in freeze-thaw enviroment
Steel rusts, is heavy to handle, and can damage finished concrete or asphalt
Both can become uneven over time, so the load distribution is no longer predictable

UHMWPE pads, machined from UHMWPE HDPE sheets and plates or HDPE sheets, stay:

Corrosion-free
Waterproof
Chemically resistant

So the mechanical behaviour of your pad is stable from job to job.
Stable pads + known soil conditions = more repeatable control of ground subsidence.

Simple Pressure Comparison: Foot Vs UHMWPE Pad

Let’s use a very simple, not-perfect numbers example.
You just want to show your customer what happens when you change pad size.

Assume:

One outrigger carries a heavy load
We compare different pad sizes

(Values below are illustrative to show the trend, not exact design data.)

Table 1 – How Pad Area Changes Ground Pressure

Scenario	Foot / Pad Size (m)	Area (m²)	Ground Pressure (relative)	Subsidence Risk (qualitative)
Bare outrigger foot only	0.25 × 0.25	0.06	Very high	Very likely, ground overstressed, big settlement
Small pad	0.5 × 0.5	0.25	High	Still risky on soft backfill, possible sink
Medium UHMWPE pad	0.8 × 0.8	0.64	Medium	Usually acceptable on firm soil, limited settlement
Large UHMWPE pad	1.0 × 1.0	1.00	Low	Inside typical soil capacity, subsidence better controlled

On site you feel it very quick:

With small pads, the outrigger sometimes “bites” into the ground.
With larger UHMWPE pads, the crane sits calm, and the lifting supervisor sleeps better that night.

Case Study: Soft Construction Site Upgraded With UHMWPE Pads

Project Background

A contractor worked on a mid-rise building project with:

Mobile crane for prefabricated concrete elements
Backfilled soil around the new basement
Old practice: mixed timber pads and small steel plates

During early lifts, they saw:

Outriggers sinking a few millimetres into the backfill
Need to stop, add more soil and compact again

After a near-miss where a lift had to be aborted because of visible tilt, management decided to try custom UHMWPE outrigger pads from Dongxing Rubber, using material from their UHMWPE sheets product line.

Implementation

The team did three simple things:

Checked the soil bearing capacity from the geotechnical report.
Selected larger UHMWPE crane pads to keep pressure within a comfortable safety margin.
Standardised pad use in the lifting plan, not just “if operator feels like it”.

Result Snapshot

After several months and many lifts, the site team reported clear differences.

Table 2 – Before/After Using UHMWPE Pads On Soft Ground

Item	Before (timber + small steel)	After (UHMWPE pads)
Ground subsidence under outriggers	Frequent small sinks, visible uneven settlement	Very limited settlement, mostly elastic recovery
Time lost to re-levelling and re-compacting	Regular delays, ad-hoc ground repairs	Only occasional minor adjustments
Operator confidence	“Crane feels like it is walking” on some lifts	Stable feeling, easier to follow the lift plan
Damage to ground / temporary slabs	Crushed spots, broken edges	Surface stays much cleaner and more uniform
Safety perception by client	Worried after near-miss event	Higher trust once pads were standardised

Is it magic? No.
It’s just better load spreading, higher compressive strength, and consistent behaviour from quality material.

Business Impact For Contractors And Rental Fleets

Reducing ground subsidence is not only about safety. It is also about business.

With UHMWPE pads you:

Cut unplanned downtime for re-levelling
Reduce risk of structural damage to finished concrete or underground services
Make your lifting plan and risk assessment more solid, not just on paper
Improve your professional image with end clients and EPCs

For rental fleets, there is another angle:

Lifting kit goes out with standardised pad sets
Less argument with customers about ground failures
Better KPI for utilisation and incident rate

These things don’t show up on the crane spec sheet, but they matter in daily operations, and your sales team can talk about them in very simple language.

Why Work With Dongxing Rubber For Custom UHMWPE Pads

Dongxing Rubber is positioned as a high-performance engineering plastic products manufacturer.
We don’t only sell flat stock. We help you turn engineering plastic into real ground protection mats and outrigger pad solutions.

From our product range:

UHMWPE & HDPE sheets and plates form the base stock for outrigger pads, crane mats, and spreader plates.
We also support ground protection mats, ice rink panels, MG engineering plastic sheets, nylon sheets, and PP/PE products for other scenes on the same jobsite.

For you as a contractor or wholesaler, that means:

OEM/ODM support for your own pad brand, backed by our OEM/ODM services
Batch production for distributors who serve multiple crane or pump companies
Custom machining for special pad shapes, lifting eyes, handles, anti-slip faces

You bring the soil bearing capacity data, typical outrigger loads, and site scenarios.
We bring the material know-how, machining, and quality control.

Together we build a pad solution that: