'was further expanded' is correct and usable in written English.
You can use it when you want to describe the process of an idea or concept being developed in more detail, usually as a result of a prior development or change. For example, "The company's marketing strategy was further expanded to include online advertising, resulting in a 50% increase in sales."
The scope of surgery was further expanded by the introduction of the operating microscope.
This was further expanded to include beam steering and the use of subapertures.
The diascia gene pool was further expanded when new species were collected in the Seventies for the Edinburgh Botanic Gardens.
The standard practice of testing these effects was further expanded by using the structural choice modelling (SCM) framework.
The study was further expanded to consider orthotropic plates and cylinders with a center hole and under uniaxial loading.
In 2012, the programme was further expanded to micro and small-sized enterprises and could be replicated in other markets like Brazil and Mexico.
Afterwards, when an additional 3% weight loss was achieved, the caloric intake was further expanded with one Prodimed being replaced with a normal meal.
Through Benita, who works in the field of postcolonial studies, Bill's intellectual life was further expanded and his circle of friends enlarged.
This range was further expanded in the late works of WB Yeats, who used ottava rima for a number of poems, including three of his greatest, Sailing to Byzantium, Among School Children and The Circus Animals' Desertion.
The railroad was further expanded in the 1880s and early 1890s to reach about 9,000 miles (14,480 km), but it lost some of this mileage in a reorganization brought on by the financial crisis of 1893.
The study used full-scale experiments in a test room in Aalborg, Denmark, to verify the performance of the control strategy, and the study was further expanded with annual simulations of the office room at different locations.
