Museum in Leiden

Aronsohn consulting engineers – Netherlands

Building use

Other

Country/Region

Netherlands

Overview

The project consists in the renovation and expansion of the Naturalis Biodiversity Center in Leiden. The proposed solution was to concentrate all the archives and depots in the 4 existing buildings and to dedicate a new construction to the museum. The new building consists in a series of parallel concrete walls, that create a sequence of 3 spaces, 21 meters in width and with variable lengths. Between each of these, a 6 meter space is used for circulation and service. Each 21-meter wide space is vertically divided in series of rooms with different heights.

Basic information (construction date, number of stories, gross floor area, adopted design code, engineer(s), Contractor(s), etc.)

Construction date: 2016-2019
Number of stories: 5
Gross floor area: 38,000m2 GLA, of which 19,000m2 renovation in the old building, 3,000m2 laboratory building and 17,000m2 new construction
Adopted design code: Eurocode
Engineer(s): Aronsohn Constructies raadgevende ingenieurs bv
Contractor(s): J.P. van Eesteren TBI

Issue and/or innovation

The size of the rooms always varies in one direction. In the other direction that measure has much more regularity and is which is also the smallest, namely 21 m. That is why the span direction has also been chosen in the direction of the smallest span.

Reason for composite solution

The height of the room influenced the choice of floor type, mainly because of the construction method. When determining the center-to-center distance of the beams, the desire to be able to regularly hang large objects was considered and this dictated the choice of lattice steel beams and, consequently, of the composite floor solution. It would have been possible to design the 21m long beams in prestressed concrete but this would have caused problems with the infrastructure for the building installations or the exhibition setups, perpendicular to the beam axis.

Specific solution/technical details

Truss steel beams have been used with a center to center distance of 3 m and a span of 21 meters. Their total height of 1450 mm which includes the thickness of the concrete floor (150 mm) as described below. The floor is composed with self-supporting prestressed precast concrete slabs of 90 mm thick on top, from beam to beam. A 60 mm pressure layer has been applied over these slabs, acting compositely thanks to shear studs. This ensures the distribution of vertical loads and the disc effect of the floor. The trusses are designed as beams on two hinges with verticals and tension diagonals. The distance between the verticals is 3 m. This size corresponds to the desired positions of the hanging points. The bottom rail is an HEB200 profile. The diagonals and verticals are also HE profiles, but vary in weight from 200B to 140A. The top rail, which also had to provide sufficient support for the floor slabs, consists of a composite profile with a wide top flange. Stud dowels are welded to the top flange for the interaction of steel with concrete. This concrete flange only contributes to stiffness and tilting stability and not to strength.

Impact or effectiveness

The 3m spacing between the lattice beams can carry large point loads. The requested design load at the bottom of 50 kg/m2 has been worked out for the beams as seven point loads of 450 kg each or one point load of 1500 kg.

References / Technical Papers Content

Henkens G., De Koning K., Cekem K., 2019, “Gebouw in vier enorme plakken”, Cement, Number 5, p. 6-16
https://www.cementonline.nl/artikelen/gebouw-in-vier-plakken