Solid Manhole

Introduction

The Vanstone Solid Manhole is a reinforced precast concrete inspection / service chamber or handhole suitable for underground telecoms services, more specific fibre optic installations. It is equipped with 8 knock out holes of 130 mm diameter, 4 unistruts vertically bolted on, a drainage sump, and a precast concrete lid that can be bolted down.

This type of manhole is available in a 'solid type' where the floor and walls are monolithic and a 'split type' with a loose floor. The last is for installers who prefer to lay the sleeves / pipes / cables first after which the manhole is placed over those services. For this purpose the end knock-outs are slotted down to floor level.

In order to facilitate the need for some variety in depth, two options are available: a 'Shallow' manhole (in solid and loose floors) and a wall extension for the loose floor type.

Solid type: Walls and floor in one piece.

 

 Split type: Walls and floor in two pieces.
For the Split type a wall extension may be added, which deepens the manhole by 350mm. The wall extension has the same knock-outs as the standard manhole walls. By using the standard walls on top of the wall extension, another eight knock-outs is effectively added higher up in the manhole.
Wall extension fits under the walls of the Split type, which in turn sits on the loose floor (not shown). Internal depth 1100mm.
 
Also in lockable steel lid (remote, programmable) for high security and full traffic loadings.
Refer : Dartcom (Pty) Ltd.
  click to enlarge

 

Design 

The Vanstone Solid Manhole has been designed in accordance with SABS 0100-1 2000 “The structural use of concrete” to safely withstand a static wheel load of 100kN. Although the lid is designed for the given loading and each lid is individually cast for each manhole to sit perfectly and eliminate rocking under traffic, concrete is a low ductility material and its durability under high volumes of heavy vehicle traffic is not proven nor guaranteed. For these situations special heavy traffic lids comprising steel as base material that is filled in with concrete should be used.

 

The tops of the walls are lined with 2 mm folded steel plate to protect the exposed edge against traffic.

Design Criteria

  • Limit state: Ultimate
  • Imposed load: 100 kN static wheel loads acting vertically on lid.
  • Load factor: 1.6
  • Material safety factors: Steel 1.15; Concrete 1.5;
  • Analysis: Static, simply supported.
  • Concrete strength: 35 Mpa
  • Reinforcing: High tensile steel main reinforcing to SABS 920

During installation (courtesy Muvoni Weltex)

Dimensions

(all dimensions in mm)
 Dimension Standard
size
With wall
extension
Shallow
type

External:

Length
Width
Height

 

1200
840
850

 

1200
840
1200

 

1200
840
600

Internal:

Length
Width
Depth

 

1000
640
750

 

1000
640
1100

 

1000
640
500

Wall thickness (min)
100
100
100
Lid thickness 100 100 100
 

Equipment list

    • Knock-outs: 8 x 130mm dia
    • Unistruts: 4 x 400mm long, size 41.3 x 20.6 bolted on. Hot dipped galvanized.
    • Anchor nuts: 4 x M16 nuts and sleeves cast into support rim. Zinc plated.
    • Bolt sleeves: 2 x suitable for M16 alancap bolts. Zinc plated. Bolts not supplied.
    • Lifting boxes: 4 x slotted, also acting as ventilation opening. Hot dipped galvanized.
    • Drainage sump 200 x 200 x 50 mm deep with weep hole.

More information

Credits

We would like to give credit to the following organisations who either initiated the product or contributed to its improvement and extending it for wider application.

  • Muvoni Weltex Network Technologies: Initial requirement and development for first installation. Anti-corrosion improvements.
  • MCT: Development of the lockable lid
  • Dark Fibre Africa: Development of the shallow handhole
  • Plessey: Development of the split type.
  • Alcatel-Lucent: Development of the 350mm wall extension to obtain a deeper manhole.
  • Vodacom: Development of standard specification