RS485 IC Termination Resistor Configuration
Typically resistors disposed like that are intended to put a differential voltage (within the acceptable common mode range) on the RS-485 receiver that is large enough to drive the output into a known state with the bus open, however they are too large to reliably do that with the 75176, so they don't do much of value. For more appropriate value resistors Rf, the termination resistor Rt has to be increased such that: 

\$\tfrac{1}{Z_0}= \tfrac{1}{R_T} + \tfrac{2}{R_F} \$

.. to match the characteristic impedance of the twisted pair. 

The amount of offset they add (~30mV with the cable open) is less than the typical hysteresis of 50mV, let alone whatever offset the receiver has (&lt;200mV) and noise immunity. 

Since those resistors are the opposite of the usual bus idle state that may be an error. You can replace the 75176s in your system with similar devices (eg. SN65HVD12) that build in an offset voltage (of the usually desired polarity) if you want that functionality with your current layout (and simply don't populate the 10K resistors). Of course all the receivers have to have this bias built in. 

Here is the usual connection scheme from this TI document: