I.up [美 əp, 英 ʌp]副up often appears as the second element of certain verb structures in English (back up, pick up, sit up, etc). For translations, see the relevant verb entry (back, pick, sit, etc).
In the end, when the judge comes to check the condition of the chawl, the landlord's men prop up the place, thus convincing the judge that all is well.
The purpose of these reforms, however, was to prop up the existing centrally planned economy, unlike later reforms, which tended toward market socialism.