UCLH PROTON BEAM THERAPY CENTRE

UCLH PROTON BEAM THERAPY CENTRE

Leveraging the benefits of geotechnical software and modelling

The team Bouygues UK – Principal Contractor

CampbellReith – Principal Designer

McGee – Demolition, Excavation

Dam Structures – Propping

Fayat – Diaphragm Walling, Piling

Stuart Well – Dewatering

Getec – Monitoring

Byrne Looby – Dwall and Piling Designer

Bell Johnson – Prop Designer

A-squared – Independent Design Review for Bouygues

One of the first two high energy Proton Beam Therapy facilities being delivered for the NHS

Going underground• Land scarcity and value in London’s

West End

• Proton Beam Therapy unit below ground

• New Day Surgery unit with eight surgery theatres also below ground

• Modern purpose-built in-patient facility above ground (105 beds) and Europe’s largest centre for the treatment of blood disorders

• Private patient unit at levels 4 and 5

Page 5 of xx

The PBT ‘Basement’

UCLH in numbers

80km3 excavation

28.5metres deep

1:5000differential settlement

Description of Geotechnical Aspects of the Project;

1. Benefits from the site investigation2. Sources of ground movement 3. Impact assessment studies4. Considering both temporary and permanent works5. Ensuring compatibility of all construction processes6. Predicted v measured prop loads

Page 8 of xx

Phase 1

• Two previous GIs on the site, incl 2 BHs to 45m through LC, LG, Upnor Fm, TS into chalk.

• Some data lost, but GIs showed marked difference in depth to base of London Clay across the site - c 4m over c25m

• Further research revealed fault identified during construction of Macmillan Cancer Centre to south. Also LG contains significant laterally variable sand layers

• Intrusive investigation designed to target these.

Phase 2

• 4 BHs to investigate potential faulted zone incl 1 no triple barrel rotary cored hole for high quality samples to allow small strain testing

• BHs clearly showed fault with base of LC 4m shallower in SW than in majority of site

• One BH passed through faulted zone – numerous water strikes (5 no in LC and LG incl one under 20m head of subartesian pressure).

• Series of piezometers at various depths allowed piezometric profile to be determined.

Careful desk study research, targeted intrusive investigation and attention to quality of sampling and testing resulted in a well-defined ground model and good quality data for further assessment and effective design.

Site Investigation

Geological fault

• Lambeth Group 5-6 metres shallower beneath south-west of site

• Numerous water strikes (sub-artesian) and sand layers passing through most sensitive part of site

Geology

Page 10 of xx

• Demolition & Removal

• Underpinning

• Excavation

• Temporary Works

• D Wall installation

• Pile installation

• Wall movements

• Propping

• Load transfer between Temporary & Permanent Works

• Long term settlement / uplift

Sources of New Ground Movements

Page 11 of xx

Surrounding structures and infrastructureParamount Court and other buildings

Infrastructure

• Brick sewers >1m diameter on all four sides

• 450 diameter cast iron trunk main

• HPPE water mains on all four sides

• London Underground Northern line

➢ Detailed GMA and damage assessments

➢ Complex geometry – combined varied software outputs and published data

➢ Calculated displacement, compressive, axial and tensile strains, radius of curvature

Page 12 of xx

Proximity of neighbours

Existing deep pile removal on perimeter of excavation

Jeremy Bentham pub and Paramount Court ‘on the edge’ of the excavation

Page 13 of xx

• Camden Basement Impact assessment process to achieve planning

• Required to demonstrate PBT centre could be constructed without significant impact to water environment (subterranean flows and surface water), without damage >Burland category 2 damage to surrounding structures and without unacceptable damage to surrounding highways.

• Thames Water ground movement and damage assessment

• London Underground ground movement and damage assessment

• Building damage assessments for Paramount Court and Jeremy Bentham pub.

Ground movement and building damage assessments undertaken using combination of approaches and software, calibrated against experience and case study data.

Numerous Impact Assessments

Page 14 of xx

Size and plan area of the excavation and unbalanced props loads• Top-down nodes to break-up horizontal

props and restrict movement

• Bespoke CHS to accommodate non-standard dimensions

• King posts plunged into piles to reduce buckling lengths

• Iteration with D-wall design to account for unbalanced loads

• Strutting layer levels set out above raft and intermediate slabs level to make strutting layout independent from permanent structures layout

Page 15 of xx

Predicted v Measured Prop Loads

Average


RD: Real data

A2: A-squared prediction (SLS)

Des: As per design (SLS)

Percent deviation

(+) overestimated

(-) underestimated

RD 1750 kN

A2 2315 kN

Des 2575 kN

RD 1100 kN

A2 2655 kN

Des 4004 kN

RD 1100 kN

A2 4418 kN

Des 4072 kN

RD 4500 kN

A2 5481 kN

Des 4481 kN

RD 2800 kN

A2 3225 kN

Des 2070 kN

RD 2200 kN

A2 3261 kN

Des 3907 kN

32%

47%

22%

0%

15%

-26%

48%

78%

141%

264%

302%

270%15%

-26%

LEVEL 1


RD 4100 kN

A2 5289 kN

Des 3790 kN

RD 8000 kN

A2 9111 kN

Des 6305 kN

RD 7500 kN

A2 12548 kN

Des 8710 kN

RD 11000 kN

A2 17919 kN

Des 14164 kN

RD 7000 kN

A2 13333 kN

Des 6911 kN

RD 5000 kN

A2 14800 kN

Des 9639 kN

29%

-8%

63%

29%

14%

-21%

67%

16%

90%

-1%

196%

93%

RD: Real data



Percent deviation

(+) overestimated

(-) underestimated15%

-26%

LEVEL 2


RD 2100 kN

A2 2753 kN

Des 1788 kN

RD 4900 kN

A2 5459 kN

Des 2974 kN

RD 7100 kN

A2 6873 kN

Des 1514 kN

RD 9750 kN

A2 9879 kN

Des 7572 kN

RD 4250 kN

A2 7085 kN

Des 3227 kN

RD 7100 kN

A2 8277 kN

Des 5508 kN

31%

-15%

1%

-22%

67%

-24%

11%

-39%

-3%

-79%

17%

-22%

RD 6100 kN

A2 6025 kN

Des 6384 kNRD 5900 kN

A2 3866 kN

Des 4185 kN

-1%

5% -34%

-29% RD: Real data



Percent deviation

(+) overestimated

(-) underestimated15%

-26%

LEVEL 3


Page 20 of xx

The value added by developing underground

Significant geotechnical and location challenges overcome

Efficient and collaborative delivery generating value and quality

Outstanding engagement with local and engineering communities and other stakeholders

Geotechnical Engineers have an important role to play

Summary

UCLH PROTON BEAM THERAPY CENTRE

Leveraging the benefits of geotechnical software and modelling

Documents

UCLH PROTON BEAM THERAPY CENTRE